Ion implantation apparatus and ion implantation method

ABSTRACT

An ion implantation apparatus includes an implantation processing chamber, a high voltage unit, and a high-voltage power supply system. In the implantation processing chamber ions are implanted into a workpiece. The high voltage unit includes an ion source unit for generating the ions, and a beam transport unit provided between the ion source unit and the implantation processing chamber. The high-voltage power supply system applies a potential to the high voltage unit under any one of a plurality of energy settings. The high-voltage power supply system includes a plurality of current paths formed such that a beam current flowing into the workpiece is returned to the ion source unit, and each of the plurality of energy settings is associated with a corresponding one of the plurality of current paths.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an ion implantation, and moreparticularly to an ion implantation apparatus and an ion implantationmethod.

2. Description of the Related Art

In a certain ion implantation apparatus, an ion source is connected to apower supply thereof such that an ion beam having a small amount of beamcurrent is extracted from the ion source. In this apparatus, theconnection between the ion source and the power supply may be modifiedsuch that an ion beam having a large amount of beam current is extractedfrom the ion source.

Another ion implantation apparatus includes an ion source, anacceleration tube, and an electric circuit connecting power suppliesthereof, so as to implant ions into a target at high ion energy. Theelectric circuit is provided with a selector switch for switching theconnection so as to implant ions at low ion energy.

Attempts to extend the operating range of the ion implantation apparatusto some degree have been made as described above. However, a realisticproposal to the extension of the operating range beyond the existingcategories is rare.

Generally, ion implantation apparatuses are classified into threecategories: a high-current ion implantation apparatus, a medium-currention implantation apparatus, and a high energy ion implantationapparatus. Since practical design requirements are different for eachcategory, an apparatus of one category and an apparatus of anothercategory may have significantly different configurations in, forexample, beamline. Therefore, in the use of the ion implantationapparatus (for example, in a semiconductor manufacturing process), it isconsidered that apparatuses of different categories have nocompatibility. That is, for particular ion implantation processing, anapparatus of a particular category is selected and used. Therefore, fora variety of ion implantation processing, it is necessary to own varioustypes of ion implantation apparatuses.

SUMMARY OF THE INVENTION

An exemplary object of an aspect of the present invention is to providean ion implantation apparatus and an ion implantation method which canbe used in a wide range, for example, an ion implantation apparatuswhich can serve as both a high-current ion implantation apparatus and amedium-current ion implantation apparatus, and an ion implantationmethod.

According to an aspect of the present invention, there is provided anion implantation apparatus including: an implantation processing chamberfor implanting ions into a workpiece; a high voltage unit including anion source unit for generating the ions, and a beam transport unitprovided between the ion source unit and the implantation processingchamber; and a high-voltage power supply system configured to apply apotential to the high voltage unit under any one of a plurality ofenergy settings, wherein the high-voltage power supply system includes aplurality of current paths formed such that a beam current flowing intothe workpiece is returned to the ion source unit, and each of theplurality of energy settings is associated with a corresponding one ofthe plurality of current paths.

According to an aspect of the present invention, there is provided anion implantation method including: selecting one of a plurality ofenergy settings; applying a potential to a high voltage unit of an ionimplantation apparatus, based on a selected energy setting; andimplanting ions into a workpiece under the selected energy setting,wherein the ion implantation apparatus includes a plurality of currentpaths formed such that a beam current flowing into the workpiece isreturned to an ion source unit, and each of the plurality of energysettings is associated with a corresponding one of the plurality ofcurrent paths.

Also, while arbitrary combinations of the above components or thecomponents or representations of the present invention are mutuallysubstituted among methods, apparatuses, systems, and programs, these arealso effective as the aspects of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described, by way of example only, withreference to the accompanying drawings which are meant to be exemplary,not limiting, and wherein like elements are numbered alike in severalFigures, in which:

FIG. 1 is a diagram schematically illustrating ranges of an energy and adose amount in several types of typical ion implantation apparatuses;

FIG. 2 is a diagram schematically illustrating an ion implantationapparatus according to an embodiment of the present invention;

FIG. 3 is a diagram schematically illustrating an ion implantationapparatus according to an embodiment of the present invention;

FIG. 4 is a flowchart illustrating an ion implantation method accordingto an embodiment of the present invention;

FIG. 5A is a plan view illustrating a schematic configuration of an ionimplantation apparatus according to an embodiment of the presentinvention, and FIG. 5B is a side view illustrating a schematicconfiguration of an ion implantation apparatus according to anembodiment of the present invention;

FIG. 6 is a diagram schematically illustrating a configuration of apower supply of an ion implantation apparatus according to an embodimentof the present invention;

FIG. 7 is a diagram schematically illustrating a configuration of apower supply of an ion implantation apparatus according to an embodimentof the present invention;

FIG. 8A is a diagram illustrating a voltage in an ion implantationapparatus according to an embodiment of the present invention, and FIG.8B is a diagram illustrating an energy in an ion implantation apparatusaccording to an embodiment of the present invention;

FIG. 9A is a diagram illustrating a voltage in an ion implantationapparatus according to an embodiment of the present invention, and FIG.9B is a diagram illustrating an energy in an ion implantation apparatusaccording to an embodiment of the present invention;

FIG. 10 is a flowchart illustrating an ion implantation method accordingto an embodiment of the present invention;

FIG. 11 is a diagram schematically illustrating ranges of an energy anda dose amount in an ion implantation apparatuses according to anembodiment of the present invention;

FIG. 12 is a diagram schematically illustrating ranges of an energy anda dose amount in an ion implantation apparatuses according to anembodiment of the present invention;

FIG. 13 is a diagram describing the use of a typical ion implantationapparatus; and

FIG. 14 is a diagram describing the use of an ion implantation apparatusaccording to an embodiment of the present invention.

FIG. 15 is a diagram illustrating a schematic configuration of an ionimplantation apparatus according to an embodiment of the presentinvention;

FIG. 16 is a diagram illustrating a schematic configuration of an ionimplantation apparatus according to an embodiment of the presentinvention;

FIG. 17 is a diagram illustrating a schematic configuration of an ionimplantation apparatus according to an embodiment of the presentinvention;

FIG. 18 is a diagram illustrating a schematic configuration of an ionimplantation apparatus according to an embodiment of the presentinvention;

FIG. 19 is a diagram illustrating a schematic configuration of an ionimplantation apparatus according to an embodiment of the presentinvention; and

FIG. 20 is a diagram illustrating a schematic configuration of an ionimplantation apparatus according to an embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

The invention will now be described by reference to the preferredembodiments. This does not intend to limit the scope of the presentinvention, but to exemplify the invention.

Hereinafter, embodiments of the present invention will be described indetail with reference to the drawings. Also, in the description of thedrawings, the same reference numerals are assigned to the samecomponents, and a redundant description thereof is appropriatelyomitted. Also, the configurations described below are exemplary, and donot limit the scope of the present invention. For example, in thefollowing, a semiconductor wafer is described as an example of an objectto which an ion implantation is performed, but other materials ormembers may also be used.

First, a description will be given of circumstances that led to anembodiment of the present invention to be described below. An ionimplantation apparatus can select an ion species to be implanted and setan energy and a dose amount thereof, based on desired properties to beestablished within a workpiece. Generally, ion implantation apparatusesare classified into several categories according to the ranges of energyand dose amount of ions to be implanted. As representative categories,there are a high-dose high-current ion implantation apparatus(hereinafter, referred to as HC), a medium-dose medium-current ionimplantation apparatus (hereinafter, referred to as MC), and a highenergy ion implantation apparatus (hereinafter, referred to as HE).

FIG. 1 schematically illustrates the energy ranges and the dose rangesof a typical serial-type high-dose high-current ion implantationapparatus HC, a serial-type medium-dose medium-current ion implantationapparatus MC, and a serial-type high energy ion implantation apparatusHE. In FIG. 1, a horizontal axis represents the dose, and a verticalaxis represents the energy. The dose is the number of ions (atoms)implanted per unit area (for example, cm²), and the total amount ofimplanted material is provided by a time integral of ion current. Theion current provided by the ion implantation is generally expressed asmA or μA. The dose is also referred to as an implantation amount or adose amount. In FIG. 1, the energy and dose ranges of the HC, the MC,and the HE are indicated by symbols A, B, and C, respectively. These area set range of implantation conditions required according toimplantation conditions (also called a recipe) for each implantation,and represent practically reasonable apparatus configuration categoriesmatched with the implantation conditions (recipe), consideringpractically allowable productivity. Each of the illustrated rangesrepresents an implantation condition (recipe) range that can beprocessed by the apparatus of each category. The dose amount representsan approximate value when a realistic processing time is assumed.

The HC is used for ion implantation in a relatively low energy range ofabout 0.1 to 100 keV and in a high dose range of about 1×10¹⁴ to 1×10¹⁷atoms/cm². The MC is used for ion implantation in a medium energy rangeof about 3 to 500 keV and in a medium dose range of about 1×10¹¹ to1×10¹⁴ atoms/cm². The HE is used for ion implantation in a relativelyhigh energy range of about 100 keV to 5 MeV and in a relatively low doserange of about 1×10¹⁰ to 1×10¹³atoms/cm². In this way, the broad rangesof the implantation conditions having about five digits for the energyrange and about seven digits for the dose ranges are shared by the HC,the MC, and the HE. However, these energy ranges or dose ranges are arepresentative example, and are not strict. Also, the way of providingthe implantation conditions is not limited to the dose and the energy,but is various. The implantation conditions may be set by a beam currentvalue (representing an area integral beam amount of a beamcross-sectional profile by a current), a throughput, implantationuniformity, and the like.

Since the implantation conditions for ion implantation processinginclude particular values of energy and dose, the implantationconditions can be expressed as individual points in FIG. 1. For example,an implantation condition a has values of a high energy and a low dose.The implantation condition a is in the operating range of the MC and isalso in the operating range of the HE. The ion implantation can beprocessed accordingly using the MC or the HE. An implantation conditionb is a medium energy/dose and the ion implantation can be processed byone of the HC, MC, and HE. An implantation condition c is a mediumenergy/dose and the ion implantation can be processed by the HC or theMC. An implantation condition d is a low energy/a high dose and can beprocessed by only the HC.

The ion implantation apparatus is an equipment essential to theproduction of semiconductor devices, and the improvement of performanceand productivity thereof has an important meaning to a device maker. Thedevice maker selects an apparatus, which is capable of realizingimplantation characteristics necessary for a device to be manufactured,among a plurality of ion implantation apparatus categories. At thistime, the device maker determines the number of apparatuses of thecategory, considering various circumstances such as the realization ofthe best manufacturing efficiency, the cost of ownership of theapparatus, and the like.

It is assumed that an apparatus of a certain category is used at a highoperating rate and an apparatus of another category has a relativelysufficient processing capacity. At this time, if the former apparatuscannot be replaced with the latter apparatus in order to obtain adesired device because implantation characteristics are strictlydifferent for each category, the failure of the former apparatus cause abottleneck on production processes, and thus overall productivity isimpaired. Such trouble may be avoided to some extent by assuming afailure rate and the like in advance and determining a numberconfiguration based on that.

When a manufacturing device is changed due to a change in demand or atechnical advance and the number configuration of necessary apparatusesis changed, apparatuses become lacking or a non-operating apparatusoccurs and thus an operating efficiency of the apparatuses may bereduced. Such trouble may be avoided to some extent by predicting thetrend of future products and reflecting the predicted trend to thenumber configuration.

Even though the apparatus can be replaced with an apparatus of anothercategory, the failure of the apparatus or the change of themanufacturing device may reduce the production efficiency or lead towasted investment for the device maker. For example, in some cases, amanufacturing process having been mainly processed till now by amedium-current ion implantation apparatus is processed by a high-currention implantation apparatus due to the change of the manufacturingdevice. If doing so, the processing capacity of the high-current ionimplantation apparatus becomes lacking, and the processing capacity ofthe medium-current ion implantation apparatus becomes surplus. If it isexpected that the state after the change will not change for a longperiod of time, the operating efficiency of the apparatus can beimproved by taking measures of purchasing a new high-current ionimplantation apparatus and selling the medium-current ion implantationapparatus having been owned. However, when a process is frequentlychanged, or such a change is difficult to predict, a trouble may becaused in production.

In practice, a process having already been performed in an ionimplantation apparatus of a certain category in order to manufacture acertain device cannot be immediately used in an ion implantationapparatus of another category. This is because a process of matchingdevice characteristics on the ion implantation apparatus is required.That is, device characteristics obtained by performing a process withthe same ion species, energy, and dose amount in the new ionimplantation apparatus may be significantly different from devicecharacteristics obtained in the previous ion implantation apparatus.Various conditions other than the ion species, the energy, and the doseamount, for example, a beam current density (that is, a dose rate), animplantation angle, or an overspray method of an implantation region,also affect the device characteristics. Generally, when the categoriesare different, apparatus configurations also are different. Therefore,even though the ion species, the energy, and the dose amount arespecified, it is impossible to automatically match the other conditionsaffecting the device characteristics. These conditions depend onimplantation methods. Examples of the implantation methods include amethod of relative movement between a beam and a workpiece (for example,a scanning beam, a ribbon beam, a two-dimensional wafer scanning, or thelike), a batch type and a serial type to be described below.

In addition, rough classification of the high-dose high-current ionimplantation apparatus and the high energy ion implantation apparatusinto a batch type and the medium-dose medium-current ion implantationapparatus into a serial type also increases a difference between theapparatuses. The batch type is a method of processing a plurality ofwafers at one time, and these wafers are disposed on, for example, thecircumference. The serial type is a method of processing wafers one byone and is also called a single wafer type. Also, in some cases, thehigh-dose high-current ion implantation apparatus and the high energyion implantation apparatus are configured as the serial type.

Also, a beamline of the batch-type high-dose high-current ionimplantation apparatus is typically made shorter than that of theserial-type medium-dose medium-current ion implantation apparatus by arequest on beamline design according to high-dose high-current beamcharacteristics. This is done for suppressing beam loss caused bydivergence of ion beams in a low energy/high beam current condition inthe design of the high-dose high-current beamline. In particular, thisis done for reducing a tendency to expand outward in a radial direction,so-called a beam blow-up, because ions forming the beam include chargedparticles repelling each other. The necessity for such design is moreremarkable when the high-dose high-current ion implantation apparatus isthe batch type than when that is the serial type.

The beamline of the serial-type medium-dose medium-current ionimplantation apparatus is made relatively long for ion beam accelerationor beam forming. In the serial-type medium-dose medium-current ionimplantation apparatus, ions having considerable momentum are moving athigh speed. The momentum of the ions increases while the ions passthrough one or several of acceleration gaps added to the beamline. Also,in order to modify a trajectory of particles having considerablemomentum, a focusing portion needs to be relatively long enough to fullyapply a focusing power.

Since the high energy ion implantation apparatus adopts a linearacceleration method or a tandem acceleration method, it is essentiallydifferent from an acceleration method of the high-dose high-current ionimplantation apparatus or the medium-dose medium-current ionimplantation apparatus. This essential difference is equally appliedwhen the high energy ion implantation apparatus is the serial type orthe batch type.

As such, the ion implantation apparatuses HC, MC and HE are recognizedas completely different apparatuses because the beamline types or theimplantation methods are different according to categories. A differencein configuration between apparatuses of different categories isrecognized as inevitable. Among the different types of apparatuses suchas HC, MC and HE, process compatibility considering the influence on thedevice characteristics is not guaranteed.

Therefore, it is preferable that the ion implantation apparatus has abroader energy range and/or dose range than the apparatus of theexisting category. In particular, it is desirable to provide an ionimplantation apparatus capable of implantation in a broad range ofenergy and dose amount including at least two existing categories,without changing the type of the implantation apparatus.

Also, in recent years, the mainstream is that all implantationapparatuses adopt the serial type. It is therefore desirable to providean ion implantation apparatus that has a serial-type configuration andalso has a broad energy range and/or dose range.

Also, the HE uses an essentially different acceleration method, and theHC and the MC are common in that ion beams are accelerated ordecelerated by a DC voltage. Therefore, there is a probability that theHC and the MC can share the beamline. It is therefore desirable toprovide an ion implantation apparatus that can serve as both the HC andthe MC.

The apparatus capable of operating at a broad range helps to improveproductivity or operating efficiency in view of device makers.

Also, the medium-current ion implantation apparatus MC can operate in ahigh energy range and a low dose range as compared with the high-currention implantation apparatus HC. Therefore, in this application, themedium-current ion implantation apparatus MC is also referred to as alow-current ion implantation apparatus. Likewise, regarding themedium-current ion implantation apparatus MC, the energy and the doseare also referred to as high energy and low dose, respectively.Alternatively, regarding the high-current ion implantation apparatus HC,the energy and the dose are also referred to as low energy and highdose, respectively. However, these expressions in this application arenot intended to restrictively indicate only the energy range and thedose range of the medium-current ion implantation apparatus MC, but maymean “a high (or low) energy (or dose) range” literally according to thecontext.

FIG. 2 is a diagram schematically illustrating an ion implantationapparatus 100 according to an embodiment of the present invention. Theion implantation apparatus 100 is configured to perform ion implantationprocessing on a surface of a workpiece W according to given ionimplantation conditions. The ion implantation conditions include, forexample, an ion species to be implanted into the workpiece W, an iondose amount, and ion energy. The workpiece W is, for example, asubstrate, or, for example, a wafer. Therefore, in the following, theworkpiece W is also referred to as a substrate W for convenience ofdescription. This is not intended to limit a target of the implantationprocessing to a particular object.

The ion implantation apparatus 100 includes an ion source 102, abeamline device 104, and an implantation processing chamber 106. Also,the ion implantation apparatus 100 includes a vacuum exhaust system (notillustrated) for providing desired vacuum environments to the ion source102, the beamline device 104, and the implantation processing chamber106.

The ion source 102 is configured to generate ions to be implanted intothe substrate W. The ion source 102 provides the beamline device 104with an ion beam B1 accelerated and extracted from the ion source 102 byan extraction electrode unit 118 that is an example of a component foradjusting a beam current. Hereinafter, this may be also referred to asan initial ion beam B1.

The beamline device 104 is configured to transport ions from the ionsource 102 to the implantation processing chamber 106. The beamlinedevice 104 provides a beamline for transporting the ion beam. Thebeamline is a passage of the ion beam and may be also said as a path ofbeam trajectory. The beamline device 104 performs operations includingdeflection, acceleration, deceleration, shaping, and scanning, withrespect to the initial ion beam B1, thereby forming an ion beam B2.Hereinafter, this may be also referred to as an implantation ion beamB2. The beamline device 104 includes a plurality of beamline componentsarranged for such beam operations. In this manner, the beamline device104 provides the implantation processing chamber 106 with theimplantation ion beam B2.

The implantation ion beam B2 has a beam irradiation region 105 in theplane perpendicular to a beam transport direction (or a direction alonga beam trajectory) of the beamline device 104. Generally, the beamirradiation region 105 has a width including the width of the substrateW. For example, when the beamline device 104 includes a beam scanningdevice scanning a spot-shaped ion beam, the beam irradiation region 105is an elongated irradiation region extending over a scanning range alonga longitudinal direction perpendicular to the beam transport direction.Also, likewise, when the beamline device 104 includes a ribbon beamgenerator, the beam irradiation region 105 is an elongated irradiationregion extending in a longitudinal direction perpendicular to the beamtransport direction. However, the elongated irradiation region is across-section of a corresponding ribbon beam. The elongated irradiationregion is longer than the width (diameter when the substrate W iscircular) of the substrate W in a longitudinal direction.

The implantation processing chamber 106 includes a workpiece holder 107holding the substrate W such that the substrate W receives theimplantation ion beam B2. The workpiece holder 107 is configured to movethe substrate W in a direction perpendicular to the beam transportdirection of the beamline device 104 and the longitudinal direction ofthe beam irradiation region 105. That is, the workpiece holder 107provides a mechanical scan of the substrate W. In this application, themechanical scan is the same as reciprocating motion. Also, the“perpendicular direction” is not limited to only a strict right angle.For example, when the implantation is performed in a state in which thesubstrate W is inclined in a vertical direction, the “perpendiculardirection” may include such an inclined angle.

The implantation processing chamber 106 is configured as a serial-typeimplantation processing chamber. Therefore, the workpiece holder 107typically holds one sheet of the substrate W. However, like the batchtype, the workpiece holder 107 may include a support holding a pluralityof (for example, small) substrates, and may be configured tomechanically scan the plurality of substrates by linearly reciprocatingthe support. In another embodiment, the implantation processing chamber106 maybe configured as a batch-type implantation processing chamber. Inthis case, for example, the workpiece holder 107 may include a rotatingdisk that rotatably holds a plurality of substrates W on thecircumference of the disk. The rotating disk may be configured toprovide a mechanical scanning.

FIG. 3 illustrates an example of the beam irradiation region 105 and therelevant mechanical scanning. The ion implantation apparatus 100 isconfigured to perform ion implantation by a hybrid scanning method usingboth one-dimensional beam scanning S_(B) of the spot-shaped ion beam B2and one-dimensional mechanical scanning S_(M) of the substrate W. On theside of the workpiece holder 107, a beam measurement device 130 (forexample, Faraday cup) is provided to overlap the beam irradiation region105, and the measurement result may be provided to a control unit 116.

In this manner, the beamline device 104 is configured to supply theimplantation processing chamber 106 with the implantation ion beam B2having the beam irradiation region 105. The beam irradiation region 105is formed to irradiate the implantation ion beam B2 across the substrateW in cooperation with the mechanical scanning of the substrate W.Therefore, ions can be implanted into the substrate W by the relativemovement of the substrate W and the ion beam.

In another embodiment, the ion implantation apparatus 100 is configuredto perform ion implantation by a ribbon beam+wafer scanning method usingboth the ribbon-shaped ion beam B2 and the one-dimensional mechanicalscanning of the substrate W. The horizontal width of the ribbon beam isexpanded while maintaining uniformity, and the substrate W is scanned soas to intersect with the ribbon beam. In a further embodiment, the ionimplantation apparatus 100 may be configured to perform ion implantationby a method of two-dimensionally mechanically scanning the substrate Win a state in which the beam trajectory of the spot-shaped ion beam B2is fixed.

Also, the ion implantation apparatus 100 is not limited to a particularimplantation method for implanting ions across a broad region on thesubstrate W. An implantation method using no mechanical scanning is alsopossible. For example, the ion implantation apparatus 100 may beconfigured to perform ion implantation by a two-dimensional beamscanning method of two-dimensionally scanning the substrate W with thespot-shaped ion beam B2. Alternatively, the ion implantation apparatus100 maybe configured to perform ion implantation by a large-size beammethod using the two-dimensionally expanded ion beam B2. The large-sizebeam is expanded to make abeam size equal to or larger than a substratesize while maintaining uniformity, and can process the entire substrateat one time.

Although details will be described below, the ion implantation apparatus100 may be operated under a first beamline setting S1 for high-doseimplantation or a second beamline setting S2 for low-dose implantation.Therefore, the beamline device 104 has the first beamline setting S1 orthe second beamline setting S2 during operations. The two settings aredetermined to generate the ion beams for different ion implantationconditions under the common implantation method. Thus, in the firstbeamline setting S1 and the second beamline setting S2, the beam centertrajectories being the reference of the ion beams B1 and B2 areidentical to each other. The beam irradiation regions 105 are alsoidentical to each other in the first beamline setting S1 and the secondbeamline setting S2.

The beam center trajectory being the reference refers to a beamtrajectory when beam is not scanned in the beam scanning method. Also,in the case of the ribbon beam, the beam center trajectory being thereference corresponds to a locus of a geometric center of a beamcross-section.

The beamline device 104 may be divided into a beamline upstream part onthe ion source 102 side and a beamline downstream part on theimplantation processing chamber 106 side. In the beamline upstream part,for example, a mass spectrometer 108 including a mass analysis magnetand a mass analysis slit is provided. The mass spectrometer 108 performsmass spectrometry on the initial ion beam B1 and provides only necessaryion species to the beamline downstream part. In the beamline downstreampart, for example, a beam irradiation region determination unit 110 isprovided to determine the beam irradiation region 105 of theimplantation ion beam B2.

The beam irradiation region determination unit 110 is configured to emitthe ion beam having the beam irradiation region 105 (for example, theimplantation ion beam B2) by applying either (or both) of an electricfield and a magnetic field to the incident ion beam (for example, theinitial ion beam B1). In an embodiment, the beam irradiation regiondetermination unit 110 includes a beam scanning device and a beamparallelizing device. Examples of the beamline components will bedescribed below with reference to FIG. 5.

Also, it should be understood that the division into the upstream partand the downstream part, as above-described, is mentioned forconveniently describing a relative position relationship of thecomponents in the beamline device 104. Therefore, for example, acomponent in the beamline downstream part may be disposed at a placecloser to the ion source 102 away from the implantation processingchamber 106. The opposite holds true as well. Therefore, in anembodiment, the beam irradiation region determination unit 110 mayinclude a ribbon beam generator and a beam parallelizing device, and theribbon beam generator may include the mass spectrometer 108.

The beamline device 104 includes an energy adjustment system 112 and abeam current adjustment system 114. The energy adjustment system 112 isconfigured to adjust implantation energy to the substrate W. The beamcurrent adjustment system 114 is configured to adjust the beam currentin a broad range so as to change a dose amount implanted into thesubstrate W in a broad range. The beam current adjustment system 114 isprovided to adjust the beam current of the ion beam quantitatively(rather than qualitatively). In an embodiment, the adjustment of the ionsource 102 can be also used to adjust the beam current. In this case,the beam current adjustment system 114 may be considered to include theion source 102. Details of the energy adjustment system 112 and the beamcurrent adjustment system 114 will be described below.

Also, the ion implantation apparatus 100 includes a control unit 116 forcontrolling all or part of the ion implantation apparatus 100 (forexample, all or part of the beamline device 104). The control unit 116is configured to select any one from a plurality of beamline settingsincluding the first beamline setting S1 and the second beamline settingS2, and operate the beamline device 104 under the selected beamlinesetting. Specifically, the control unit 116 sets the energy adjustmentsystem 112 and the beam current adjustment system 114 according to theselected beamline setting, and controls the energy adjustment system 112and the beam current adjustment system 114. Also, the control unit 116may be a dedicated controller for controlling the energy adjustmentsystem 112 and the beam current adjustment system 114.

The control unit 116 is configured to select a beamline setting suitablefor given ion implantation conditions among the plurality of beamlinesettings including the first beamline setting S1 and the second beamlinesetting S2. The first beamline setting S1 is suitable for transport of ahigh-current beam for high-dose implantation into the substrate W.Therefore, for example, the control unit 116 selects the first beamlinesetting S1 when a desired ion dose amount implanted into the substrate Wis in the range of about 1×10¹⁴ to 1×10¹⁷ atoms/cm². Also, the secondbeamline setting S2 is suitable for transport of a low-current beam forlow-dose implantation into the substrate. Therefore, for example, thecontrol unit 116 selects the second beamline setting S2 when a desiredion dose amount implanted into the substrate W is in the range of about1×10¹¹ to 1×10¹⁴ atoms/cm². Details of the beamline settings will bedescribed below.

The energy adjustment system 112 includes a plurality of energyadjustment elements arranged along the beamline device 104. Theplurality of energy adjustment elements is disposed at fixed positionson the beamline device 104. As illustrated in FIG. 2, the energyadjustment system 112 includes, for example, three adjustment elements,specifically, an upstream adjustment element 118, an intermediateadjustment element 120, and a downstream adjustment element 122. Each ofthese adjustment elements includes one or more electrodes configured toexert an electric field for accelerating or decelerating the initial ionbeam B1 and/or the implantation ion beam B2.

The upstream adjustment element 118 is provided in the upstream part ofthe beamline device 104, for example, the most upstream part of thebeamline device 104. The upstream adjustment element 118 includes, forexample, an extraction electrode system for extracting the initial ionbeam B1 from the ion source 102 to the beamline device 104. Theintermediate adjustment element 120 is installed in the middle portionof the beamline device 104 and includes, for example, an electrostaticbeam parallelizing device. The downstream adjustment element 122 isprovided in the downstream part of the beamline device 104 and includes,for example, an acceleration/deceleration column. The downstreamadjustment element 122 may include an angular energy filter (AEF)disposed in the downstream of the acceleration/deceleration column.

Also, the energy adjustment system 112 includes a power supply systemfor the above-described energy adjustment elements. This will bedescribed below with reference to FIGS. 6 and 7. Also, the plurality ofenergy adjustment elements may be provided in any number anywhere on thebeamline device 104, which is not limited to the illustratedarrangement. Also, the energy adjustment system 112 may include only oneenergy adjustment element.

The beam current adjustment system 114 is provided in the upstream partof the beamline device 104, and includes a beam current adjustmentelement 124 for adjusting the beam current of the initial ion beam B1.The beam current adjustment element 124 is configured to block at leasta portion of the initial ion beam B1 when the initial ion beam B1 passesthrough the beam current adjustment element 124. In an embodiment, thebeam current adjustment system 114 may include a plurality of beamcurrent adjustment elements 124 arranged along the beamline device 104.Also, the beam current adjustment system 114 may be provided in thedownstream part of the beamline device 104.

The beam current adjustment element 124 includes a movable portion foradjusting a passage region of the ion beam cross-section perpendicularto the beam transport direction of the beamline device 104. According tothe movable portion, the beam current adjustment element 124 constitutesa beam limiting device having a variable-width slit or a variable-shapeopening for limiting a portion of the initial ion beam B1. Also, thebeam current adjustment system 114 includes a driving device forcontinuously or discontinuously adjusting the movable portion of thebeam current adjustment element 124.

Additionally or alternatively, the beam current adjustment element 124may include a plurality of adjustment members (for example, adjustmentaperture) each having a plurality of beam passage regions havingdifferent areas and/or shapes. The beam current adjustment element 124may be configured to switch the adjustment member disposed on the beamtrajectory among the plurality of adjustment members. In this manner,the beam current adjustment element 124 may be configured to adjust thebeam current stepwise.

As illustrated, the beam current adjustment element 124 is a beamlinecomponent separate from the plurality of energy adjustment elements ofthe energy adjustment system 112. By separately installing the beamcurrent adjustment element and the energy adjustment element, the beamcurrent adjustment and the energy adjustment may be individuallyperformed. This may increase the degree of freedom in the setting of thebeam current range and the energy range in the individual beamlinesettings.

The first beamline setting S1 includes a first energy setting for theenergy adjustment system 112 and a first beam current setting for thebeam current adjustment system 114. The second beamline setting S2includes a second energy setting for the energy adjustment system 112and a second beam current setting for the beam current adjustment system114. The first beamline setting S1 is directed to the low energy andhigh-dose ion implantation, and the second beamline setting S2 isdirected to the high energy and low-dose ion implantation.

Therefore, the first energy setting is determined to be suitable for thetransport of the low energy beam as compared with the second energysetting. Also, the second beam current setting is determined to reducethe beam current of the ion beam as compared with the first beam currentsetting. By combining the beam current adjustment and the irradiationtime adjustment of the implantation ion beam B2, a desired dose amountcan be implanted into the substrate W.

The first energy setting includes a first power supply connectionsetting that determines the connection between the energy adjustmentsystem 112 and the power supply system thereof. The second energysetting includes a second power supply connection setting thatdetermines the connection between the energy adjustment system 112 andthe power supply system thereof. The power supply connection settingsare determined such that the intermediate adjustment element 120 and/orthe downstream adjustment element 122 generate an electric field forhelping the beam transport. For example, the beam parallelizing deviceand/or the acceleration/deceleration column, as a whole, are configuredto decelerate the implantation ion beam B2 under the first energysetting and accelerate the implantation ion beam B2 under the secondenergy setting. Due to the power supply connection settings, a voltageadjustment range of each adjustment element of the energy adjustmentsystem 112 is determined. In the adjustment range, a voltage of thepower supply corresponding to each adjustment element can be adjusted toprovide a desired implantation energy to the implantation ion beam B2.

The first beam current setting includes a first opening setting thatdetermines the ion beam passage region of the beam current adjustmentelement 124. The second beam current setting includes a second openingsetting that determines the ion beam passage region of the beam currentadjustment element 124. The second opening setting is determined suchthat the ion beam passage region is small as compared with the firstopening setting. The opening settings determine, for example, themovable range of the movable portion of the beam current adjustmentelement 124. Alternatively, the opening settings may determine theadjustment member to be used. In this manner, the ion beam passageregion corresponding to the desired beam current within the adjustmentrange determined by the opening settings may be set to the beam currentadjustment element 124. The ion beam passage region can be adjusted suchthat a desired dose amount is implanted into the substrate W within aprocessing time permitted to the ion implantation processing.

Thus, the beamline device 104 has a first energy adjustment range underthe first beamline setting S1 and has a second energy adjustment rangeunder the second beamline setting S2. In order to enable abroad range ofthe adjustment, the first energy adjustment range has a portionoverlapping the second energy adjustment range. That is, two adjustmentranges overlap each other in at least the ends thereof. The overlappingportion may be a straight-line in the diagram schematically illustratingrange of an energy and dose of ion implantation apparatuses. In thiscase, two adjustment ranges contact each other. In another embodiment,the first energy adjustment range may be separated from the secondenergy adjustment range.

Likewise, the beamline device 104 has a first dose adjustment rangeunder the first beamline setting S1 and has a second dose adjustmentrange under the second beamline setting S2. The first dose adjustmentrange has a portion overlapping the second dose adjustment range. Thatis, two adjustment ranges overlap each other in at least the endsthereof. The overlapping portion may be a straight-line in the diagramschematically illustrating range of an energy and dose of ionimplantation apparatuses. In this case, two adjustment ranges contacteach other. In another embodiment, the first dose adjustment range maybe separated from the second dose adjustment range.

In this manner, the beamline device 104 is operated in a first operationmode under the first beamline setting S1. The first operation mode maybe referred to as a low energy mode (or a high-dose mode). Also, thebeamline device 104 is operated in a second operation mode under thesecond beamline setting S2. The second operation mode may be referred toas a high energy mode (or a low-dose mode). The first beamline settingS1 can be also referred to as a first implantation setting configurationsuitable for the transport of a low energy/high-current beam for thehigh-dose implantation into the workpiece W. The second beamline settingS2 can be also referred to as a second implantation settingconfiguration suitable for the transport of a high energy/low-currentbeam for the low-dose implantation into the workpiece W.

An operator of the ion implantation apparatus 100 can switch thebeamline settings before a certain ion implantation processing isperformed, depending on the implantation conditions of the processing.Therefore, the broad range from the low energy (or high-dose) to thehigh energy (or low-dose) can be processed by one ion implantationapparatus.

Also, the ion implantation apparatus 100 corresponds to the broad rangeof the implantation conditions in the same implantation method. That is,the ion implantation apparatus 100 processes a broad range withsubstantially the same beamline device 104. Also, the ion implantationapparatus 100 has the serial-type configuration that is recentlybecoming the mainstream. Therefore, although details will be describedbelow, the ion implantation apparatus 100 is suitable for use as ashared unit of the existing ion implantation apparatuses (for example,HC and MC).

The beamline device 104 can also be considered to include a beam controldevice for controlling the ion beam, abeam conditioning device forconditioning the ion beam, and a beam shaping device for shaping the ionbeam. The beamline device 104 supplies the ion beam having the beamirradiation region 105 exceeding the width of the workpiece W in theimplantation processing chamber 106 by using the beam control device,the beam conditioning device, and the beam shaping device. In the ionimplantation apparatus 100, the beam control device, the beamconditioning device, and the beam shaping device may have the samehardware configuration in the first beamline setting S1 and the secondbeamline setting S2. In this case, the beam control device, the beamconditioning device, and the beam shaping device may be disposed withthe same layout in the first beamline setting S1 and the second beamlinesetting S2. Therefore, the ion implantation apparatus 100 may have thesame installation floor area (so-called footprint) in the first beamlinesetting S1 and the second beamline setting S2.

The beam center trajectory being the reference is a beam trajectory thatis a locus of geometric center of the beam cross-section without beamscanning in the beam scanning method. Also, in the case of the ribbonbeam that is a stationary beam, the beam center trajectory being thereference corresponds to a locus of a geometric center of the beamcross-section, regardless of a change in the beam cross-sectional shapein the implantation ion beam B2 of the downstream part.

The beam control device may include the control unit 116. The beamconditioning device may include the beam irradiation regiondetermination unit 110. The beam conditioning device may include anenergy filter or a deflection element. The beam shaping device mayinclude a first XY convergence lens 206, a second XY convergence lens208, and a Y convergence lens 210, which are to be described below.

It can be considered that, in the case of the beam scanning method, theinitial ion beam B1 takes a single beam trajectory in the upstream partof the beamline device 104, and in the downstream part the implantationion beam B2 takes a plurality of beam trajectories due to the beamscanning and parallelizing with reference to the beam center trajectorybeing the reference. However, in the case of the ribbon beam, it becomesa beam irradiation zone because the beam cross-sectional shape of thesingle beam trajectory is changed and the beam width is widened. Thus,the beam trajectory is also single. According to this view, the beamirradiation region 105 may be also referred to as an ion beam trajectoryzone. Therefore, in the ion implantation apparatus 100, the implantationion beam B2 has the same ion beam trajectory zone in the first beamlinesetting S1 and the second beamline setting S2.

FIG. 4 is a flowchart illustrating an ion implantation method accordingto an embodiment of the present invention. This ion implantation methodis suitable for use in the ion implantation apparatus 100. This methodis performed by the control unit 116. As illustrated in FIG. 4, thismethod includes a beamline setting selecting step (S10) and an ionimplantation step (S20).

The control unit 116 selects a beamline setting suitable for given ionimplantation conditions among a plurality of beamline settings (S10). Asdescribed above, the plurality of beamline settings includes a firstbeamline setting S1 suitable for transport of a high-current beam forhigh-dose implantation into a workpiece, and a second beamline settingS2 suitable for transport of a low-current beam for low-doseimplantation into a workpiece. For example, the control unit 116 selectsthe first beamline setting S1 when a desired ion dose amount implantedinto a substrate W exceeds a threshold value, and selects the secondbeamline setting S2 when the desired ion dose amount is smaller than thethreshold value. Also, as described below, the plurality of beamlinesettings (or implantation setting configurations) may include a thirdbeamline setting (or third implantation setting configuration) and/or afourth beamline setting (or fourth implantation setting configuration).

When the first beamline setting S1 is selected, the control unit 116sets the energy adjustment system 112 by using the first energy setting.The energy adjustment system 112 and the power supply thereof areconnected according to a first power supply connection setting. Also,the control unit 116 sets the beam current adjustment system 114 byusing the first beam current setting. Therefore, the ion beam passageregion (or adjustment range thereof) is set according to the firstopening setting. Likewise, when the second beamline setting S2 isselected, the control unit 116 sets the energy adjustment system 112 byusing the second energy setting, and sets the beam current adjustmentsystem 114 by using the second beam current setting.

The selecting process step may include a process step of adjusting thebeamline device 104 in the adjustment range according to the selectedbeamline setting. In the adjusting process step, each adjustment elementof the beamline device 104 is adjusted within a corresponding adjustmentrange so as to generate the ion beam of a desired implantationcondition. For example, the control unit 116 determines a voltage of apower supply corresponding to each adjustment element of the energyadjustment system 112 so as to obtain a desired implantation energy.Also, the control unit 116 determines the ion beam passage region of thebeam current adjustment element 124 so as to obtain a desiredimplantation dose amount.

In this manner, the control unit 116 operates the ion implantationapparatus 100 under the selected beamline setting (S20). Theimplantation ion beam B2 having the beam irradiation region 105 isgenerated and supplied to the substrate W. The implantation ion beam B2scans the entire substrate W in cooperation with the mechanical scanningof the substrate W (or with the beam alone). As a result, ions areimplanted into the substrate W at the energy and dose amount of thedesired ion implantation conditions.

The serial-type high-dose high-current ion implantation apparatus, whichis being used in device production, currently adopts a hybrid scanningmethod, a two-dimensional mechanical scanning method, and a ribbonbeam+wafer scanning method. However, the two-dimensional mechanicalscanning method has a limitation in increase of a scanning speed due toa load of mechanical driving mechanism of the mechanical scanning, andthus, the two-dimensional mechanical scanning method disadvantageouslycannot suppress implantation non-uniformity sufficiently. Also, in theribbon beam+wafer scanning method, uniformity is easily degraded whenthe beam size is expanded in a horizontal direction. Therefore, inparticular, there are problems in the uniformity and the identity ofbeam angle in the low-dose condition (low beam current condition).However, when the obtained implantation result is within an allowablerange, the ion implantation apparatus of the present invention may beconfigured by the two-dimensional mechanical scanning method or theribbon beam+wafer scanning method.

On the other hand, the hybrid scanning method can achieve excellentuniformity in the beam scanning direction by adjusting the bean scanningspeed at high accuracy. Also, by performing the beam scanning at asufficient high speed, implantation non-uniformity in the wafer scanningdirection can be sufficiently suppressed. Therefore, the hybrid scanningmethod is considered as optimal over a broad range of the dosecondition.

FIG. 5A is a plan view illustrating a schematic configuration of an ionimplantation apparatus 200 according to an embodiment of the presentinvention, and FIG. 5B is a side view illustrating a schematicconfiguration of an ion implantation apparatus 200 according to anembodiment of the present invention. The ion implantation apparatus 200is an embodiment when the hybrid scanning method is applied to the ionimplantation apparatus 100 illustrated in FIG. 2. Also, like the ionimplantation apparatus 100 illustrated in FIG. 2, the ion implantationapparatus 200 is a serial-type apparatus.

As illustrated, the ion implantation apparatus 200 includes a pluralityof beamline components. The beamline upstream part of the ionimplantation apparatus 200 includes, in order from the upstream side, anion source 201, a mass analysis magnet 202, a beam dump 203, a resolvingaperture 204, a current suppression mechanism 205, a first XYconvergence lens 206, abeam current measurement device 207, and a secondXY convergence lens 208. An extraction electrode 218 (see FIGS. 6 and 7)for extracting ions from the ion source 201 is provided between the ionsource 201 and the mass analysis magnet 202.

A scanner 209 is provided between the beamline upstream part and thebeamline downstream part. The beamline downstream part includes, inorder from the upstream side, a Y convergence lens 210, a beamparallelizing mechanism 211, an AD (Accel/Decel) column 212, and anenergy filter 213. A wafer 214 is disposed in the most downstream partof the beamline downstream part. The beamline components from the ionsource 201 to the beam parallelizing mechanism 211 are accommodated in aterminal 216.

The current suppression mechanism 205 is an example of theabove-described beam current adjustment system 114. The currentsuppression mechanism 205 is provided for switching a low-dose mode anda high-dose mode. The current suppression mechanism 205 includes, forexample, a continuously variable aperture (CVA). The CVA is an aperturecapable of adjusting an opening size by a driving mechanism. Therefore,the current suppression mechanism 205 is configured to operate in arelatively small opening size adjustment range in the low-dose mode, andoperate in a relatively large opening size adjustment range in thehigh-dose mode. In an embodiment, in addition or alternative to thecurrent suppression mechanism 205, a plurality of resolving apertures204 having different opening widths may be configured to operate withdifferent settings in the low-dose mode and the high-dose mode.

The current suppression mechanism 205 serves to help beam adjustmentunder the low beam current condition by limiting an ion beam amountarriving at the downstream. The current suppression mechanism 205 isprovided in the beamline upstream part (that is, from the ion extractionfrom the ion source 201 to the upstream side of the scanner 209).Therefore, the beam current adjustment range can be increased. Also, thecurrent suppression mechanism 205 may be provided in the beamlinedownstream part.

The beam current measurement device 207 is, for example, a movable flagFaraday.

The first XY convergence lens 206, the second XY convergence lens 208,and the Y convergence lens 210 constitute the beam shaping device foradjusting the beam shape in the vertical and horizontal directions (beamcross-section in an XY plane). As such, the beam shaping device includesa plurality of lenses arranged along the beamline between the massanalysis magnet 202 and the beam parallelizing mechanism 211. The beamshaping device can use the convergence/divergence effect of these lensesin order to appropriately transport the ion beam up to the downstream inabroad range of energy/beam current condition. That is, the ion beam canbe appropriately transported to the wafer 214 in any condition of lowenergy/low beam current, low energy/high beam current, high energy/lowbeam current, and high energy/high beam current.

The first XY convergence lens 206 is, for example, a Q lens. The secondXY convergence lens 208 is, for example, an XY-direction einzel lens.The Y convergence lens 210 is, for example, a Y-direction einzel lens orQ lens. Each of the first XY convergence lens 206, the second XYconvergence lens 208, and the Y convergence lens 210 maybe a single lensor a group of lenses. In this manner, the beam shaping device isdesigned to appropriately control the ion beam from the low energy/highbeam current condition having a beam self-divergence problem caused by alarge beam potential to the high energy/low beam current having a beamcross-sectional shape control problem caused by a small beam potential.

The energy filter 213 is, for example, an angular energy filter (AEF)having a deflection electrode or a deflection electromagnet, or both ofthe defection electrode and the deflection electromagnet.

The ions generated in the ion source 201 are accelerated with anextraction electric field (not illustrated). The accelerated ions aredeflected in the mass analysis magnet 202. In this manner, only ionshaving a predetermined energy and a mass-to-charge ratio pass throughthe resolving aperture 204. Subsequently, the ions are guided to thescanner 209 through the current suppression mechanism (CVA) 205, thefirst XY convergence lens 206, and the second XY convergence lens 208.

The scanner 209 reciprocally scans the ion beam in a horizontaldirection (which may be a vertical direction or an oblique direction) byapplying either (or both) of a periodic electric field and a periodicmagnetic field. Due to the scanner 209, the ion beam is adjusted suchthat the ion beam is uniformly implanted in a horizontal direction onthe wafer 214. The traveling direction of the ion beam 215 with whichthe scanner 209 scans can be parallelized by the beam parallelizingmechanism 211 using the application of either (or both) of the electricfield and the magnetic field. Thereafter, the ion beam 215 isaccelerated or decelerated to have a predetermined energy in the ADcolumn 212 by applying the electric field. The ion beam 215 exiting theAD column 212 reaches the final implantation energy (in the low energymode, the energy may be adjusted to be higher than the implantationenergy, and the ion beam may be deflected while decelerating in theenergy filter). The energy filter 213 in the downstream of the AD column212 deflects the ion beam 215 to the wafer 214 by the application ofeither (or both) of the electric field and the magnetic field with thedeflection electrode or the deflection electromagnet. Thus, acontamination with energy other than target energy is eliminated. Inthis manner, the purified ion beam 215 is implanted into the wafer 214.

Also, the beam dump 203 is disposed between the mass analysis magnet 202and the resolving aperture 204. The beam dump 203 deflects the ion beamby applying the electric field when necessary. Therefore, the beam dump203 can control the arrival of the ion beam at the downstream at highspeed.

Next, the low energy mode and the high energy mode in the ionimplantation apparatus 200 illustrated in FIG. 5 will be described withreference to the configuration system diagram of the high-voltage powersupply system 230 illustrated in FIGS. 6 and 7. FIG. 6 illustrates apower supply switching state of the low energy mode, and FIG. 7illustrates a power supply switching state of the high energy mode.FIGS. 6 and 7 illustrate main components related to the energyadjustment of the ion beam among the beamline components illustrated inFIG. 5. In FIGS. 6 and 7, the ion beam 215 is indicated by an arrow.

As illustrated in FIGS. 6 and 7, the beam parallelizing mechanism 211(see FIG. 5) includes a double P lens 220. The double P lens 220includes a first voltage gap 221 and a second voltage gap 222 disposedspaced apart from each other along the ion movement direction. The firstvoltage gap 221 is disposed in the upstream, and the second voltage gap222 is disposed in the downstream.

The first voltage gap 221 is formed between a pair of electrodes 223 and224. The second voltage gap 222 is formed between another pair ofelectrodes 225 and 226 disposed in the downstream of the electrodes 223and 224. The first voltage gap 221 and the electrodes 223 and 224forming the gap 221 have a convex shape toward the upstream side.Conversely, the second voltage gap 222 and the electrodes 225 and 226forming the gap 222 have a convex shape toward the downstream side.Also, for convenience of description, these electrodes may be alsoreferred to as a first P lens upstream electrode 223, a first P lensdownstream electrode 224, a second P lens upstream electrode 225, and asecond P lens downstream electrode 226 below.

The double P lens 220 parallelizes the incident ion beam before emissionand adjusts the energy of the ion beam by a combination of the electricfields applied to the first voltage gap 221 and the second voltage gap222. That is, the double P lens 220 accelerates or decelerates the ionbeam by the electric fields of the first voltage gap 221 and the secondvoltage gap 222.

Also, the ion implantation apparatus 200 includes a high-voltage powersupply system 230 including a power supply for the beamline components.The high-voltage power supply system 230 includes a first power supplyunit 231, a second power supply unit 232, a third power supply unit 233,a fourth power supply unit 234, and a fifth power supply unit 235. Asillustrated, the high-voltage power supply system 230 includes aconnection circuit for connecting the first to fifth power supply units231 to 235 to the ion implantation apparatus 200.

The first power supply unit 231 includes a first power supply 241 and afirst switch 251. The first power supply 241 is provided between the ionsource 201 and the first switch 251, and is a DC power supply thatprovides the ion source 201 with a positive voltage. The first switch251 connects the first power supply 241 to a ground 217 in the lowenergy mode (see FIG. 6), and connects the first power supply 241 to aterminal 216 in the high energy mode (see FIG. 7). Therefore, the firstpower supply 241 provides a voltage V_(HV) to the ion source 201 in thelow energy mode on the basis of a ground potential. This provides thetotal ion energy as it is. On the other hand, the first power supply 241provides a voltage V_(HV) to the ion source 201 in the high energy modeon the basis of a terminal potential.

The second power supply unit 232 includes a second power supply 242 anda second switch 252. The second power supply 242 is provided between theterminal 216 and the ground 217, and is a DC power supply that providesthe terminal 216 with one of positive and negative voltages by theswitching of the second switch 252. The second switch 252 connects anegative electrode of the second power supply 242 to the terminal 216 inthe low energy mode (see FIG. 6), and connects a positive electrode ofthe second power supply 242 to the terminal 216 in the high energy mode(see FIG. 7). Therefore, the second power supply 242 provides a voltageV_(T) (V_(T)<0) to the terminal 216 in the low energy mode on the basisof the ground potential. On the other hand, the second power supply 242provides a voltage V_(T) (V_(T)>0) to the terminal 216 in the highenergy mode on the basis of the ground potential.

Therefore, an extraction voltage V_(EXT) of the extraction electrode 218is V_(EXT)=V_(HV)−V_(T) in the low energy mode, and is V_(EXT)=V_(HV) inthe high energy mode. When a charge of an ion is q, the final energy isqV_(HV) in the low energy mode, and is q(V_(HV)+V_(T)) in the highenergy mode.

The third power supply unit 233 includes a third power supply 243 and athird switch 253. The third power supply 243 is provided between theterminal 216 and the double P lens 220. The third power supply 243includes a first P lens power supply 243-1 and a second P lens powersupply 243-2. The first P lens power supply 243-1 is a DC power supplythat provides a voltage V_(AP) to the first P lens downstream electrode224 and the second P lens upstream electrode 225 on the basis of theterminal potential. The second P lens power supply 243-2 is a DC powersupply that provides a voltage V_(DP) to a destination through the thirdswitch 253 on the basis of the terminal potential. The third switch 253is provided between the terminal 216 and the double P lens 220 toconnect one of the first P lens power supply 243-1 and the second P lenspower supply 243-2 to the second P lens downstream electrode 226 by theswitching. Also, the first P lens upstream electrode 223 is connected tothe terminal 216.

The third switch 253 connects the second P lens power supply 243-2 tothe second P lens downstream electrode 226 in the low energy mode (seeFIG. 6), and connects the first P lens power supply 243-1 to the secondP lens downstream electrode 226 in the high energy mode (see FIG. 7).Therefore, the third power supply 243 provides a voltage V_(DP) to thesecond P lens downstream electrode 226 in the low energy mode on thebasis of the terminal potential. On the other hand, the third powersupply 243 provides a voltage V_(AP) to the second P lens downstreamelectrode 226 in the high energy mode on the basis of the terminalpotential.

The fourth power supply unit 234 includes a fourth power supply 244 anda fourth switch 254. The fourth power supply 244 is provided between thefourth switch 254 and the ground 217 and is a DC power supply thatprovides a negative voltage to an exit (that is, the downstream end) ofthe AD column 212. The fourth switch 254 connects the fourth powersupply 244 to the exit of the AD column 212 in the low energy mode (seeFIG. 6), and connects the exit of the AD column 212 to the ground 217 inthe high energy mode (see FIG. 7). Therefore, the fourth power supply244 provides a voltage V_(ad) to the exit of the AD column 212 in thelow energy mode on the basis of the ground potential. On the other hand,the fourth power supply 244 is not used in the high energy mode.

The fifth power supply unit 235 includes a fifth power supply 245 and afifth switch 255. The fifth power supply 245 is provided between thefifth switch 255 and the ground 217. The fifth power supply 245 isprovided for the energy filter (AEF) 213. The fifth switch 255 isprovided for switching the operation modes of the energy filter 213. Theenergy filter 213 is operated in a so-called offset mode in the lowenergy mode, and is operated in a normal mode in the high energy mode.The offset mode is an operation mode of the AEF in which an averagevalue of the positive electrode and the negative electrode is a negativepotential. The beam convergence effect of the offset mode can preventbeam loss caused by the beam divergence in the AEF. The normal mode isan operation mode of the AEF in which an average value of the positiveelectrode and the negative electrode is the ground potential.

The ground potential is provided to the wafer 214.

FIG. 8A illustrates an example of a voltage applied to each portion ofthe ion implantation apparatus 200 in the low energy mode, and FIG. 8Billustrates an example of energy of the ion in each portion of the ionimplantation apparatus 200 in the low energy mode. FIG. 9A illustratesan example of a voltage applied to each portion of the ion implantationapparatus 200 in the high energy mode, and FIG. 9B illustrates anexample of energy of the ion in each portion of the ion implantationapparatus 200 in the high energy mode. The vertical axes in FIGS. 8A and9A represent the voltage, and the vertical axes in FIGS. 8B and 9Brepresent the energy. In the horizontal axes of the respective drawings,locations in the ion implantation apparatus 200 are represented bysymbols a to g. The symbols a, b, c, d, e, f, and g represent the ionsource 201, the terminal 216, the acceleration P lens (first P lensdownstream electrode 224), the deceleration P lens (second P lensdownstream electrode 226), the exit of the AD column 212, the energyfilter 213, and the wafer 214, respectively.

The double P lens 220 has a configuration that uses the acceleration Plens c alone, or uses the deceleration P lens d alone, or uses both ofthe acceleration P lens c and the deceleration P lens d, when necessaryaccording to the implantation condition. In the configuration that usesboth of the acceleration P lens c and the deceleration P lens d, thedouble P lens 220 can be configured to change the distribution of theacceleration and deceleration effects by using both of the accelerationeffect and the deceleration effect. In this case, the double P lens 220can be configured such that a difference between the incident beamenergy to the double P lens 220 and the exit beam energy from the doubleP lens 220 is used to accelerate or decelerate the beam. Alternatively,the double P lens 220 can be configured such that the difference betweenthe incident beam energy and the exit beam energy becomes zero, andthus, the beam is neither accelerated nor decelerated.

As an example, as illustrated, in the low energy mode, the double P lens220 is configured to decelerate the ion beam in the deceleration P lensd, accelerate the ion beam in the acceleration P lens c to some extentwhen necessary, and thereby the ion beam is decelerated as a whole. Onthe other hand, in the high energy mode, the double P lens 220 isconfigured to accelerate the ion beam only in the acceleration P lens c.Also, in the high energy mode, the double P lens 220 may be configuredto decelerate the ion beam in the deceleration P lens d to some extentwhen necessary, as long as the ion beam is accelerated as a whole.

Since the high-voltage power supply system 230 is configured as above,the voltages applied to several regions on the beamline can be changedby the switching of the power supply. Also, the voltage applicationpaths in some regions can also be changed. By using these, it ispossible to switch the low energy mode and the high energy mode in thesame beamline.

In the low energy mode, the potential V_(HV) of the ion source 201 isdirectly applied on the basis of the ground potential. Therefore, ahigh-accuracy voltage application to the source unit is possible, andthe accuracy of energy setting can be increased during the ionimplantation at low energy. Also, by setting the terminal voltage V_(T),the P lens voltage V_(DP), the AD column exit voltage V_(ad), and theenergy filter voltage V_(bias) to negative, it is possible to transportthe ions to the energy filter at a relatively high energy. Therefore,the transport efficiency of the ion beam can be improved, and the highcurrent can be obtained.

Also, in the low energy mode, the deceleration P lens is employed tofacilitate the ion beam transport in the high energy state. This helpsthe low energy mode coexist with the high energy mode in the samebeamline. Also, in the low energy mode, an expanded beam by design isgenerated by adjusting the convergence/divergence elements of thebeamline in order to transport the beam such that the self-divergence ofthe beam is minimized. This also helps the low energy mode coexist withthe high energy mode in the same beamline.

In the high energy mode, the potential of the ion source 201 is the sumof the acceleration extraction voltage V_(HV) and the terminal potentialV_(T). This can enable the application of the high voltage to the sourceunit, and accelerate ions at high energy.

FIG. 10 is a flowchart illustrating an ion implantation method accordingto an embodiment of the present invention. This method may be performedby, for example, the beam control device for the ion implantationapparatus. As illustrated in FIG. 10, first, the implantation recipe isselected (S100). The control device reads the recipe condition (S102),and selects the beamline setting according to the recipe condition(S104). The ion beam adjusting process is performed under the selectedbeamline setting. The adjusting process includes a beam emission andadjustment (S106) and an obtained beam checking (S108). In this manner,the preparing process for the ion implantation is ended. Next, the waferis loaded (S110), the ion implantation is performed (S112), and thewafer is unloaded (S114). Steps 110 to 114 may be repeated until thedesired number of wafers are processed.

FIG. 11 schematically illustrates a range D of energy and dose amountthat is realized by the ion implantation apparatus 200. Like in FIG. 1,FIG. 11 illustrates the range of energy and dose amount that can beprocessed in the actually allowable productivity. For comparison, rangesA, B and C of energy and dose amount of the HC, the MC, and the HEillustrated in FIG. 1 are illustrated in FIG. 11.

As illustrated in FIG. 11, it can be seen that the ion implantationapparatus 200 includes all the operation ranges of the existingapparatuses HC and MC. Therefore, the ion implantation apparatus 200 isa novel apparatus beyond the existing framework. Even one novel ionimplantation apparatus can serve as the two existing types of categoriesHC and MC while maintaining the same beamline and the implantationmethod. Therefore, this apparatus may be referred to as HCMC.

Therefore, according to the present embodiment, it is possible toprovide the HCMC in which the serial-type high-dose high-current ionimplantation apparatus and the serial-type medium-dose medium-currention implantation apparatus are configured as a single apparatus. TheHCMC can perform the implantation in a broad range of energy conditionand dose condition by changing the voltage applying method in the lowenergy condition and the high energy condition and changing the beamcurrent from high current to low current in the CVA.

Also, the HCMC-type ion implantation apparatus may not include all theimplantation condition ranges of the existing HC and MC. Considering thetradeoff of the device manufacturing cost and the implantationperformance, it may be thought to provide an apparatus having a range E(see FIG. 12) narrower than the range D illustrated in FIG. 11. In thiscase, the ion implantation apparatus having excellent practicality canbe provided as long as it covers the ion implantation conditionsrequired for the device maker.

The improvement in the operation efficiency of the apparatus realized bythe HCMC in the device manufacturing process will be described. Forexample, as illustrated in FIG. 13, it is assumed that a device makeruses six HCs and four MCs in order to process a manufacturing process X(that is, this device maker owns only the existing apparatuses HC andMC). Thereafter, the device maker changes the process X to a process Yaccording to a change in a manufacturing device. As a result, the devicemaker needs eight HCs and two MCs. The maker needs to install two moreHCs, and thus, the increase in investment and the lead time arerequired. At the same time, two MCs are not operated, and thus, themaker unnecessarily owns these. As described above, since the HC and theMC are generally different in the implantation method, it is difficultto convert the non-operating MCs to newly necessary HCs.

Next, as illustrated in FIG. 14, it is considered that the device makeruses six HCs, two MCs, and two HCMCs in order to process the process X.In this case, even when the process X is changed to the process Yaccording to the change in the manufacturing device, the HCMC can beoperated as the HC because the HCMC is the process shared machine of theHC and the MC. Therefore, additional equipment installation andnon-operation are unnecessary.

As such, there is a great merit when the device maker owns a certainnumber of HCMCs. This is because the process change of HC and the MC canbe absorbed by the HCMC. Also, when some apparatuses cannot be used dueto malfunction or maintenance, the HCMC can also be used as the HC orthe MC. Therefore, by owning the HCMC, the overall operating rate of theapparatus can be significantly improved.

Also, ultimately, it can be considered that all apparatuses are providedwith HCMCs. However, in many cases, it is practical that part of theapparatuses are provided with HCMCs considering a price differencebetween the HCMC and the HC (or MC) or the utilization of the alreadyowned HC or MC.

Also, when a type of the existing ion implantation apparatus is replacedwith other apparatuses having different methods of implanting ions intothe wafer in order for an ion implantation process to be performed, itmaybe difficult to match the implantation characteristics. This isbecause a beam divergence angle or a beam density may be different eventhough the energy and dose are matched in two types of ion implantationapparatuses for the ion implantation process. However, the HCMC canprocess the high-dose high-current ion implantation condition and themedium-dose medium-current ion implantation condition on the samebeamline (the same ion beam trajectory). In this way the HCMC canseparately use the high-dose high-current ion implantation condition andthe medium-dose medium-current ion implantation condition. Therefore, itis expected to facilitate the matching because the change in theimplantation characteristics followed by the replacement of theapparatus is sufficiently suppressed.

The HCMC is the shared machine of the HC and the MC and can also processthe implantation condition out of the operation range of the existing HCor the MC. As illustrated in FIG. 11, the HCMC is a new apparatus thatcan also process the high energy/high dose implantation (right upperregion F in the range D) and low energy/low dose implantation (leftlower region G in the range D). Therefore, in addition or alternative tothe first beamline setting S1 and the second beamline setting S2described above, in an embodiment, the ion implantation apparatus mayinclude a third beamline setting for high energy/high dose implantationand/or a fourth beamline setting for low energy/low dose implantation.

As described above, in the present embodiment, the beamlines of theserial-type high-dose high-current ion implantation apparatus and theserial-type medium-dose medium-current ion implantation apparatus arematched and shared. Moreover, a structure for switching the beamlineconfiguration is constructed. In this manner, the implantationprocessing is possible over a broad range of energy and beam currentregions on the same beamline (the same ion beam trajectory and the sameimplantation method).

The present invention has been described based on the embodiments. Thepresent invention is not limited to the embodiments, and it can beunderstood by those skilled in the art that designs can be modified invarious ways, various modifications can be made, and such modificationsfall within the scope of the present invention.

In addition or alternative to the above-described configurations, thequantitative adjustment of the beam current by the beam currentadjustment system can be configured in various ways. For example, whenthe beam current adjustment system includes a variable-width aperturearranged on the beamline, the variable-width aperture may be disposed atany arbitrary position. Therefore, the variable-width aperture may bedisposed between the ion source and the mass analysis magnet, betweenthe mass analysis magnet and the mass analysis slit, between the massanalysis slit and the beam shaping device, between the beam shapingdevice and the beam control device, between the beam control device andthe beam conditioning device, between the respective elements of thebeam conditioning device, and/or between the beam conditioning deviceand the workpiece. The variable-width aperture may be the mass analysisslit.

The beam current adjustment may be configured to adjust the amount ofion beam passing through the aperture by arranging thedivergence/convergence lens system before and/or after a fixed-widthaperture. The fixed-width aperture may be the mass analysis slit.

The beam current adjustment may be performed using an energy slitopening width variable (and/or a beamline end opening width variableslit apparatus). The beam current adjustment may be performed using ananalyzer magnet (mass analysis magnet) and/or a steerer magnet(trajectory modification magnet). The dose amount adjustment may beaccompanied by an expansion of the variable range of mechanical scanspeed (for example, from ultra-low speed to ultra-high speed) and/or achange in the number of times of the mechanical scanning.

The beam current adjustment may be performed by the adjustment of theion source (for example, amount of gas or arc current). The beam currentadjustment may be performed by the exchange of the ion source. In thiscase, the ions source for MC and the ion source for HC may beselectively used. The beam current adjustment may be performed by thegap adjustment of the extraction electrode of the ion source. The beamcurrent adjustment may be performed by providing the CVA immediatelydownstream of the ion source.

The beam current adjustment may be performed according to the change inthe vertical width of the ribbon beam. The dose amount adjustment may beperformed according to the change in the scanning speed during thetwo-dimensional mechanical scanning.

The beamline device may include a plurality of beamline componentsconfigured to operate under only one of the first beamline setting andthe second beamline setting, and thus, the ion implantation apparatusmay be configured as a high-current ion implantation apparatus or amedium-current ion implantation apparatus. That is, with the HCMC as aplatform, for example, by exchanging some beamline components, orchanging the power supply configuration, the serial-type high-dosededicated ion implantation apparatus or the serial-type medium-dosededicated ion implantation apparatus can be produced from theserial-type high-dose medium-dose wide-use ion implantation apparatus.Since it is expected to manufacture each dedicated apparatus at lowercost than the wide-use apparatus, it can contribute to reducing themanufacturing costs for the device maker.

In the MC, implantation at higher energy may be achieved by usingmultivalent ions such as divalent ions or trivalent ions. However, inthe typical ion source (thermionic emission type ion source), thegeneration efficiency of multivalent ions is much lower than thegeneration efficiency of monovalent ions. Therefore, practical doseimplantation in the high energy range is actually difficult. When amultivalent ion enhancement source, such as an RF ion source, isemployed as the ion source, tetravalent or pentavalent ions can beobtained. Therefore, more ion beams can be obtained in the higher energycondition.

Therefore, by employing the multivalent ion enhancement source, such asthe RF ion source, as the ion source, the HCMC can operate as theserial-type high energy ion implantation apparatus (HE). Therefore, aportion of the implantation condition that has been processed by onlythe serial-type high energy/low-dose ion implantation apparatus can beprocessed by the HCMC (the range of the MC illustrated in FIG. 8 maybeexpanded to include at least a portion of the range C).

Hereinafter, several aspects of the present invention will be described.

An ion implantation apparatus according to an embodiment includes: anion source for generating ions and extracting the ions as an ion beam;an implantation processing chamber for implanting the ions into aworkpiece; and a beamline device for providing a beamline to transportthe ion beam from the ion source to the implantation processing chamber,wherein the beamline device supplies the ion beam having a beamirradiation region exceeding the width of the workpiece in theimplantation processing chamber, the implantation processing chamberincludes a mechanical scanning device for mechanically scanning theworkpiece with respect to the beam irradiation region, the beamlinedevice is operated under one of a plurality of implantation settingconfigurations according to an implantation condition, the plurality ofimplantation setting configurations including a first implantationsetting configuration suitable for transport of a low energy/highcurrent beam for high-dose implantation into the workpiece, and a secondimplantation setting configuration suitable for transport of a highenergy/low current beam for low-dose implantation into the workpiece,and the beamline device is configured such that a same beam centertrajectory being a reference in the beamline is provided from the ionsource to the implantation processing chamber in the first implantationsetting configuration and the second implantation setting configuration.

An ion implantation apparatus according to an embodiment includes: anion source for generating ions and extracting the ions as an ion beam;an implantation processing chamber for implanting the ions into aworkpiece; and a beamline device for providing a beamline to transportthe ion beam from the ion source to the implantation processing chamber,wherein the ion implantation apparatus is configured to irradiate theworkpiece with the ion beam in cooperation with mechanical scanning ofthe workpiece, the beamline device is operated under one of a pluralityof implantation setting configurations according to an implantationcondition, the plurality of implantation setting configurationsincluding a first implantation setting configuration suitable fortransport of a low energy/high current beam for high-dose implantationinto the workpiece, and a second implantation setting configurationsuitable for transport of a high energy/low current beam for low-doseimplantation into the workpiece, and the beamline device is configuredsuch that a same beam center trajectory being a reference in thebeamline is provided from the ion source to the implantation processingchamber in the first implantation setting configuration and the secondimplantation setting configuration.

The beamline device may take the same implantation method in the firstimplantation setting configuration and the second implantation settingconfiguration. The beam irradiation region may be equal in the firstimplantation setting configuration and the second implantation settingconfiguration.

The beamline apparatus may include a beam conditioning device forconditioning the ion beam, and a beam shaping device for shaping the ionbeam. The beam conditioning device and the beam shaping device in thebeamline device may be disposed in the same layout in the firstimplantation setting configuration and the second implantation settingconfiguration. The beam implantation apparatus may have the sameinstallation floor area in the first implantation setting configurationand the second implantation setting configuration.

The beamline device may include a beam current adjustment system foradjusting the total amount of beam current of the ion beam. The firstimplantation setting configuration may include a first beam currentsetting for the beam current adjustment system, the second implantationsetting configuration may include a second beam current setting for thebeam current adjustment system, and the second beam current setting maybe determined to make the beam current of the ion beam smaller than thatof the first beam current setting.

The beam current adjustment system may be configured to block at least aportion of the ion beam when passing through an adjustment element. Thebeam current adjustment system may include a variable-width aperturearranged on the beamline. The beam current adjustment system may includea beamline end opening width variable slit device. The ion source may beconfigured to adjust the total amount of beam current of the ion beam.The ion source may include an extraction electrode for extracting theion beam, and the total amount of beam current of the ion beam may beadjusted by adjusting an opening of the extraction electrode.

The beamline device may include an energy adjustment system foradjusting an implantation energy of the ions into the workpiece. Thefirst implantation setting configuration may include a first energysetting for the energy adjustment system, the second implantationsetting configuration may include a second energy setting for the energyadjustment system, the first energy setting may be suitable fortransport of a lower energy beam as compared with the second energysetting.

The energy adjustment system may include a beam parallelizing device forparallelizing the ion beam. The beam parallelizing device maybeconfigured to decelerate, or decelerate and accelerate the ion beamunder the first implantation setting configuration, and accelerate, oraccelerate and decelerate the ion beam under the second implantationsetting configuration. The beam parallelizing device may include anacceleration lens for accelerating the ion beam, and a deceleration lensfor decelerating the ion beam, and may be configured to modify adistribution of acceleration and deceleration, and the beamparallelizing device may be configured to mainly decelerate the ion beamunder the first implantation setting configuration, and mainlyaccelerate the ion beam under the second implantation settingconfiguration.

The beamline device may include a beam current adjustment system foradjusting the total amount of beam current of the ion beam, and anenergy adjustment system for adjusting an implantation energy of theions into the workpiece, and may adjust the total amount of the beamcurrent and the implantation energy individually or simultaneously. Thebeam current adjustment system and the energy adjustment system may beseparate beamline components.

The ion implantation apparatus may include a control unit configured tomanually or automatically select one implantation setting configurationsuitable for a given ion implantation condition among the plurality ofimplantation setting configurations including the first implantationsetting configuration and the second implantation setting configuration.

The control unit may select the first implantation setting configurationwhen a desired ion dose amount implanted into the workpiece is in therange of about 1×10¹⁴ to 1×10¹⁷ atoms/cm², and may select the secondimplantation setting configuration when a desired ion dose amountimplanted into the workpiece is in the range of about 1×10¹¹ to 1×10¹⁴atoms/cm².

The beamline device may have a first energy adjustment range under thefirst implantation setting configuration, and may have a second energyadjustment range under the second implantation setting configuration,and the first energy adjustment range and the second energy adjustmentrange may have a partially overlapped range.

The beamline device may have a first dose adjustment range under thefirst implantation setting configuration, and may have a second doseadjustment range under the second implantation setting configuration,and the first dose adjustment range and the second dose adjustment rangemay have a partially overlapped range.

The beamline device may include a beam scanning device for providingscanning of the ion beam to form an elongated irradiation regionextending in a longitudinal direction perpendicular to a beam transportdirection. The implantation processing chamber may include a workpieceholder configured to provide mechanical scanning of the workpiece in adirection perpendicular to the longitudinal direction and the beamtransport direction.

The beamline device may include a ribbon beam generator for generating aribbon beam having an elongated irradiation region extending in alongitudinal direction perpendicular to a beam transport direction. Theimplantation processing chamber may include a workpiece holderconfigured to provide mechanical scanning of the workpiece in adirection perpendicular to the longitudinal direction and the beamtransport direction.

The implantation processing chamber may include a workpiece holderconfigured to provide mechanical scanning of the workpiece in twodirections perpendicular to each other in a plane perpendicular to thebeam transport direction.

The beamline device may be configured to be selectable from a pluralityof beamline components configured to be operated under only one of thefirst implantation setting configuration and the second implantationsetting configuration, and the ion implantation apparatus may beconfigured as a high-current dedicated ion implantation apparatus or amedium-current dedicated ion implantation apparatus.

An ion implantation method according to an embodiment includes:selecting one implantation setting configuration, with respect to abeamline device, which is suitable for a given ion implantationcondition among a plurality of implantation setting configurationsincluding a first implantation setting configuration suitable fortransport of a low energy/high current beam for high-dose implantationinto a workpiece, and a second implantation setting configurationsuitable for transport of a high energy/low current beam for low-doseimplantation into the workpiece; transporting an ion beam along a beamcenter trajectory being a reference in a beamline from an ion source toan implantation processing chamber by using the beamline device underthe selected implantation setting configuration; and irradiating theworkpiece with the ion beam in cooperation with mechanical scanning ofthe workpiece, wherein the beam center trajectory being the reference isequal in the first implantation setting configuration and the secondimplantation setting configuration.

The transporting may include adjusting an implantation dose amount intothe workpiece by adjusting the total amount of beam current of the ionbeam. The implantation dose amount may be adjusted in a first doseadjustment range under the first implantation setting configuration, andmay be adjusted in a second dose adjustment range under the secondimplantation setting configuration, the second dose adjustment rangeincluding a dose range smaller than the first dose adjustment range.

The transporting may include adjusting the implantation energy into theworkpiece. The implantation energy may be adjusted in a first energyadjustment range under the first implantation setting configuration, andmay be adjusted in a second energy adjustment range under the secondimplantation setting configuration, the second energy adjustment rangeincluding an energy range higher than the first energy adjustment range.

1. An ion implantation apparatus according to an embodiment has the samebeam trajectory and the same implantation method and has a broad energyrange by switching a connection of a power supply for deceleration as awhole and a connection of a power supply for acceleration as a whole.

2. An ion implantation apparatus according to an embodiment has the samebeam trajectory and the same implantation method and has a broad beamcurrent range by including a device for cutting a portion of beam in abeamline upstream part in a beamline capable of obtaining a highcurrent.

3. An ion implantation apparatus according to an embodiment may have thesame beam trajectory and the same implantation method and have a broadenergy range and a broad beam current range by including both of thefeatures of the embodiment 1 and the embodiment 2.

An ion implantation apparatus according to an embodiment may be anapparatus that combines a beam scanning and a mechanical wafer scanningas the same implantation method in the embodiments 1 to 3. An ionimplantation apparatus according to an embodiment maybe an apparatusthat combines a ribbon-shaped beam and a mechanical wafer scanning asthe same implantation method in the embodiments 1 to 3. An ionimplantation apparatus according to an embodiment may be an apparatusthat combines a two-dimensional mechanical wafer scanning as the sameimplantation method in the embodiments 1 to 3.

4. An ion implantation apparatus according to an embodiment isconfigured to freely select/switch a high-dose high-current ionimplantation and a medium-dose medium-current ion implantation byconfiguring a high-dose high-current ion implantation beamline componentand a medium-dose medium-current ion implantation beamline component inparallel on the same beamline (the same ion beam trajectory and the sameimplantation method), and covers a very broad energy range from lowenergy to high energy and a very broad dose range from a low dose to ahigh dose.

5. In the embodiment 4, each beamline component shared in the high doseuse and the medium dose use and each beamline component individuallyswitched in the high dose/medium dose use may be configured on the samebeamline.

6. In the embodiment 4 or 5, in order to adjust the beam current amountin a broad range, a beam limiting device (vertical or horizontalvariable-width slit, or rectangular or circular variable opening) forphysically cutting a portion of beam in a beamline upstream part may beprovided.

7. In any one of the embodiments 4 to 6, a switch controller controldevice may be provided to select a high-dose high-current ionimplantation and a medium-dose medium-current ion implantation, based ona desired ion dose amount implanted into the workpiece.

8. In the embodiment 7, the switch controller is configured to operatethe beamline in a medium-dose acceleration (extraction)/acceleration (Plens)/acceleration or deceleration (AD column) mode when a desired iondose amount implanted into the workpiece is in the medium-dosemedium-current range of about 1×10¹¹ to 1×10¹⁴ atoms/cm, and operate thebeamline in a high-dose acceleration (extraction)/deceleration (Plens)/deceleration (AD column) mode when a desired ion dose amountimplanted into the workpiece is in the high-dose high-current range ofabout 1×10¹⁴ to 1×10¹⁷ atoms/cm².

9. In any one of the embodiments 4 to 8, an apparatus for implantingions of relatively high energy by using an acceleration mode and anapparatus for implanting ions of relatively low energy by using adeceleration mode may have a mutually overlapped energy range.

10. In anyone of the embodiments 4 to 8, an apparatus for implantingions of relatively high energy by using an acceleration mode and anapparatus for implanting ions of relatively low energy by using adeceleration mode may have a mutually overlapped dose range.

11. In any one of the embodiments 4 to 6, by limiting the beamlinecomponents, the ion implantation apparatus may easily be changed to ahigh-dose high-current dedicated ion implantation apparatus or amedium-dose medium-current dedicated ion implantation apparatus.

12. In any one of the embodiments 4 to 11, the beamline configurationmay combine a beam scanning and a mechanical substrate scanning.

13. In any one of the embodiments 4 to 11, the beamline configurationmay combine a mechanical substrate scanning and a ribbon-shaped beamhaving a width equal to or greater than a width of a substrate (or waferor workpiece).

14. In any one of the embodiments 4 to 11, the beamline configurationmay include a mechanical substrate scanning in a two-dimensionaldirection.

Hereinafter, a return path of a beam current flowing into a workpiecewill be considered. The beam current flowing into the workpiece is anamount of ions implanted into the workpiece per unit time. In ionimplantation, ions are extracted from a high-voltage ion source, and theextracted ions are transported and implanted into the workpiece.Electrically, it can be considered that a voltage source (ion source)and a current source (ion beam) are connected in series. In order toestablish these as an electric circuit, a path for returning the currentfrom the current source to the voltage source, that is, a current pathfor returning the beam current flowing into the workpiece to the ionsource is required.

Also, the incident position of the ion beam is not limited to only theworkpiece. The ion beam may be incident on structures surrounding theworkpiece or other structures (for example, a workpiece holder, a wallsurface of an implantation processing chamber, and the like). Therefore,in this specification, the “beam current flowing into the workpiece” maymean the “beam current flowing into workpiece and/or other structures”.

FIGS. 15 and 16 are diagrams illustrating a schematic configuration ofan ion implantation apparatus 300 according to an embodiment of thepresent invention. A power switching state of a second energy setting(high energy mode) is illustrated in an upper part of FIG. 15, and apower switching state of a first energy setting (low energy mode) isillustrated in an upper part of FIG. 16. Also, the voltage and energyapplied to each element of the ion implantation apparatus 300 under thesecond energy setting are illustrated in a lower part of FIG. 15, andthe voltage and energy applied to each element of the ion implantationapparatus 300 under the first energy setting are illustrated in a lowerpart of FIG. 16.

The ion implantation apparatus 300 includes an ion source unit 302, abeam transport unit 304, and an implantation processing chamber 306. Thebeam transport unit 304 is provided between the ion source unit 302 andthe implantation processing chamber 306. An ion beam 307 is generated inthe ion source unit 302. The ion beam 307 is transported from the ionsource unit 302 through the beam transport unit 304 to the implantationprocessing chamber 306. The ion beam 307 is irradiated on the workpieceW held in the implantation processing chamber 306.

The basic configuration of the ion implantation apparatus 300 accordingto the present embodiment is substantially identical to that of the ionimplantation apparatus 100 or the ion implantation apparatus 200according to the respective embodiments described above. Therefore, theion source unit 302 may be the ion source 102 (see FIG. 2) or the ionsource 201 (see FIG. 5). The beam transport unit 304 may be the beamlinedevice 104 (see FIG. 2), or may include one or more of beamlinecomponents illustrated in FIG. 5. The implantation processing chamber306 may be the implantation processing chamber 106 (see FIG. 2).

A first insulating support 308 is provided between the ion source unit302 and the beam transport unit 304. The first insulating support 308 isconfigured to electrically insulate the ion source unit 302 and the beamtransport unit 304 from each other. The first insulating support 308 maystructurally support the ion source unit 302 to the beam transport unit304. A second insulating support 310 is provided between the beamtransport unit 304 and the implantation processing chamber 306. Thesecond insulating support 310 is configured to electrically insulate thebeam transport unit 304 and the implantation processing chamber 306 fromeach other. The second insulating support 310 may structurally supportthe beam transport unit 304 to the implantation processing chamber 306.

Also, the ion implantation apparatus 300 includes a high-voltage powersupply system 314 that applies a potential to a high voltage unit 312.The high voltage unit 312 includes the ion source unit 302 and the beamtransport unit 304. Since the ion source unit 302 and the beam transportunit 304 are insulated from each other, different potentials may beapplied to the ion source unit 302 and the beam transport unit 304,respectively.

An energy setting used for a particular ion implantation process isselected from a plurality of energy settings according to a given ionimplantation condition. The plurality of energy settings includes afirst energy setting suitable for transport of a low energy ion beam,and a second energy setting suitable for transport of a high energy ionbeam. Like the above-described embodiment, the first energy setting maybe referred to as a low energy mode, and the second energy setting maybe referred to as a high energy mode. As described above, the firstenergy setting may be determined to be suitable for transport of a lowenergy/high current beam, and the second energy setting may bedetermined to be suitable for transport of a high energy/low currentbeam.

Like the high-voltage power supply system 230 (see FIGS. 6 and 7), thehigh-voltage power supply system 314 is configured to be capable ofswitching the power supply connection according to the selected energysetting. The processing of switching the power supply connection may beperformed by the control unit 116 (see FIG. 2). The control unit 116 mayselect the second energy setting when desired implantation energy isequal to or greater than a certain threshold value, and select the firstenergy setting when the desired implantation energy is equal to or lessthan the certain threshold value. The threshold value may be equal tothe product of a charge q of ion and a voltage V₁ of the first powersupply 241.

Like the high-voltage power supply system 230, the high-voltage powersupply system 314 includes a first power supply 241 and a second powersupply 242. The first power supply 241 is a DC power supply configuredto apply a positive potential to the ion source unit 302. The firstpower supply 241 is a variable power supply that can control the appliedpositive potential. The first power supply 241 applies the positivepotential V₁ to the ion source unit 302, with the beam transport unit304 being set as the reference potential. To this end, the positiveterminal of the first power supply 241 is connected to the ion sourceunit 302, and the negative terminal of the first power supply 241 isconnected to a connection point 316 that takes the same potential as thebeam transport unit 304. The magnitude of the voltage applied to the ionsource unit 302 by the first power supply 241 may be equal or differentin the low energy mode and the high energy mode.

Also, the second power supply 242 is a variable DC power supplyconfigured to apply the positive or negative potential, relative to thereference potential of the workpiece W, to the beam transport unit 304.The second power supply 242 includes a positive power supply 242-1 thatprovides the positive potential to the beam transport unit 304, and anegative power supply 242-2 that provides the negative potential to thebeam transport unit 304. The positive power supply 242-1 applies thepositive potential V₂₋₁, relative to the reference potential of theworkpiece W, to the beam transport unit 304, and the negative powersupply 242-2 applies the negative potential V₂₋₂, relative to thereference potential of the workpiece W, to the beam transport unit 304.As illustrated, in the present embodiment, the workpiece W is grounded.

The high-voltage power supply system 314 differs from the high-voltagepower supply system 230 in terms of the configuration for switching thepower supply. The high-voltage power supply system 314 includes aswitching mechanism 318, and the switching mechanism 318 includes afirst switching unit 320 and a second switching unit 322. The firstswitching unit 320 is provided between the positive power supply 242-1and the connection point 316, and the second switching unit 322 isprovided between the negative power supply 242-2 and the connectionpoint 316.

The first switching unit 320 includes a resistor 324, and a connectionline 326 that bypasses the resistor 324. The resistor 324 is a returningresistor provided such that the beam current flowing from the ion beam307 to the workpiece W in the low energy mode is returned to the ionsource unit 302 through the second power supply 242. The first switchingunit 320 is configured to be switchable between a first state toserially connect the resistor 324 to the positive power supply 242-1 anda second state to serially connect the connection line 326 to thepositive power supply 242-1. The second switching unit 322 is configuredto be switchable between a first state to connect the negative powersupply 242-2 to the beam transport unit 304 and a second state todisconnect the negative power supply 242-2 from the beam transport unit304.

In the high energy mode, as illustrated in FIG. 15, the first switchingunit 320 is switched to the second state and the second switching unit322 is switched to the second state. Therefore, the negative powersupply 242-2 is disconnected from the beam transport unit 304, and thepositive power supply 242-1 is connected to the beam transport unit 304through the connection line 326. The first power supply 241 and thepositive power supply 242-1 are serially connected between the ionsource unit 302 and the ground potential.

Therefore, in the high energy mode, the total potential V₁+V₂₋₁ of thefirst power supply 241 and the positive power supply 242-1 is applied tothe ion source unit 302. The positive potential V₂₋₁ is applied to thebeam transport unit 304. Thus, the extraction voltage is V₁. Therefore,the energy E_(EXT) of the ion beam extracted from the ion source unit302 to the beam transport unit 304 is E_(EXT)=qV₁, where q is the chargeof ion. The final energy E_(IMP) is E_(IMP)=q(V₁+V₂₋₁).

At this time, as indicated by a solid arrow in FIG. 15, a second currentpath 328 is formed such that the beam current flowing from the ion beam307 to the workpiece W is returned to the ion source unit 302. Thesecond current path 328 is a path that starts from the workpiece W,passes through the positive power supply 242-1, the connection line 326,the connection point 316 (beam transport unit 304), and the first powersupply 241 in this order, and reaches the ion source unit 302. Thedirection of the current is consistent with the polarity of each of thefirst power supply 241 and the positive power supply 242-1. Thus, thesecond current path 328 can return the beam current from the workpiece Wto the ion source unit 302.

On the other hand, in the low energy mode, as illustrated in FIG. 16,the first switching unit 320 is switched to the first state and thesecond switching unit 322 is switched to the first state. Therefore, thenegative power supply 242-2 is connected to the beam transport unit 304,and the positive power supply 242-1 is connected to the beam transportunit 304 through the resistor 324. The first power supply 241 and thenegative power supply 242-2 are serially connected between the ionsource unit 302 and the ground potential.

Therefore, in the low energy mode, the total potential V_(I)+V₂₋₂ (>0)of the first power supply 241 and the negative power supply 242-2 isapplied to the ion source unit 302. The negative potential V₂₋₂ isapplied to the beam transport unit 304. Thus, the extraction voltage isV₁. Therefore, the energy E_(EXT) of the ion beam extracted from the ionsource unit 302 to the beam transport unit 304 is E_(EXT)=qV₁. The finalenergy E_(IMP) is E_(IMP)=q(V₁+V₂₋₂).

At this time, as indicated by a dashed arrow in FIG. 16, the negativepower supply 242-2 does not flow the beam current in a direction fromthe workpiece W to the ion source unit 302 because the polarity of thenegative power supply 242-2 is reverse to the beam current.

However, due to the resistor 324, a current loop is formed between thepositive power supply 242-1 and the negative power supply 242-2. Thecurrent loop is reverse to the dashed arrow, as indicated by adashed-dotted arrow. Therefore, as indicated by a solid arrow in FIG.16, a first current path 330 is formed such that the beam currentflowing from the ion beam 307 to the workpiece W is returned to the ionsource unit 302. The first current path 330 is a path that starts fromthe workpiece W, passes through the positive power supply 242-1, theresistor 324, the connection point 316 (beam transport unit 304), andthe first power supply 241 in this order, and reaches the ion sourceunit 302.

Therefore, the resistor 324 provided for forming the first current path330 is effective when the beam current of the ion beam 307 is small (forexample, in the case of about several mA). Therefore, the embodimentusing the returning resistor is suitable for a low energy/low currention beam. However, when the beam current is large (for example, in thecase of about several tens mA), the capacity of the resistor 324suitable for use is also large. Therefore, it may not be practical interms of installation cost and/or space. When the beam current is large,the amount of heat generated in the resistor 324 also increases. Thus,it may be preferable to attach a cooling device to the resistor 324.This case is also disadvantageous in terms of installation cost and/orspace. Therefore, in an embodiment to be described below, the returnpath of the beam current is formed without using the resistor 324.

FIGS. 17 and 18 are diagrams illustrating a schematic configuration ofan ion implantation apparatus 400 according to an embodiment of thepresent invention. A power switching state of a second energy setting(high energy mode) is illustrated in an upper part of FIG. 17, and apower switching state of a first energy setting (low energy mode) isillustrated in an upper part of FIG. 18. Also, the voltage and energyapplied to each element of the ion implantation apparatus 400 under thesecond energy setting are illustrated in a lower part of FIG. 17, andthe voltage and energy applied to each element of the ion implantationapparatus 400 under the first energy setting are illustrated in a lowerpart of FIG. 18.

Like the ion implantation apparatus 300 according to the embodimentdescribed with reference to FIGS. 15 and 16, the ion implantationapparatus 400 includes an ion source unit 302, a beam transport unit304, an implantation processing chamber 306, a first insulating support308, and a second insulating support 310. Also, like the ionimplantation apparatus 200 according to the embodiment described abovewith reference to FIGS. 6 and 7, the ion implantation apparatus 400includes a high-voltage power supply system 230. Therefore, the ionimplantation apparatus 400 may have the same configuration as the ionimplantation apparatus 200.

As described below in detail, the high-voltage power supply system 230includes a first current path 402 formed such that a beam currentflowing from a low energy ion beam to a workpiece W is returned to theion source unit 302 (see FIG. 18). Also, the high-voltage power supplysystem 230 includes a second current path 404 formed such that a beamcurrent flowing from a high energy ion beam to a workpiece W is returnedto the ion source unit 302 (see FIG. 17).

As described above, the high-voltage power supply system 230 includes afirst power supply unit 231 and a second power supply unit 232. Thefirst power supply unit 231 includes a first power supply 241 and afirst switch 251. The first power supply 241 is configured to apply apositive potential to the ion source unit 302. The first switch 251 is aswitching mechanism for switching a reference potential of the ionsource unit 302. The positive terminal of the first power supply 241 isconnected to the ion source unit 302, and the negative terminal of thefirst power supply 241 is connected to the first switch 251. The firstswitch 251 is configured to be switchable between a first state toconnect the negative terminal of the first power supply 241 to a portiontaking the same potential as the workpiece W and a second state toconnect the negative terminal of the first power supply 241 to the beamtransport unit 304. Since the workpiece W is grounded, the first switch251 connects the negative terminal of the first power supply 241 to aground portion 406 in the first state.

Also, an ion implantation apparatus according to another embodiment maybe configured to apply a certain potential to the workpiece W, thecertain potential being determined with respect to the referencepotential (generally, the ground portion 406). For example, the positivepotential relative to the reference potential of the workpiece W may beapplied to the workpiece W. This can transport the beam to theimplantation processing chamber at the high energy, and can implant thebeam at the low energy by decelerating the beam at the positivepotential of the workpiece W. Such technology may also help improvementof productivity.

The second power supply unit 232 includes a second power supply 242 anda second switch 252. As described above, the second power supply 242includes a positive power supply 242-1 and a negative power supply242-2. The second switch 252 is a switching mechanism for switching thepositive and negative potentials of the beam transport unit 304 withrespect to the reference potential of the workpiece W. The second switch252 is configured to be switchable between a first state to connect thenegative power supply 242-2 to the connection point 316 and a secondstate to connect the positive power supply 242-1 to the connection point316.

The second switch 252 is configured to operate in synchronization withthe first switch 251. The second switch 252 is in the first state whenthe first switch 251 is in the first state, and the second switch 252 isin the second state when the first switch 251 is in the second state.

In the high energy mode, as illustrated in FIG. 17, the first switch 251is switched to the second state and the second switch 252 is switched tothe second state. Therefore, the reference potential of the ion sourceunit 302 is set to the beam transport unit 304, and the potential of thebeam transport unit 304 is set to the positive potential relative to thereference potential of the workpiece W. The first power supply 241 andthe positive power supply 242-1 are serially connected between the ionsource unit 302 and the ground potential. The negative power supply242-2 is disconnected from the beam transport unit 304, and the firstpower supply 241 is disconnected from the ground portion 406.

In this manner, the high energy mode is determined such that a secondsource potential is applied to the ion source unit 302, and a secondbeam transport potential is applied to the beam transport unit 304. Thesecond source potential is a positive potential relative to thepotential of the beam transport unit 304. The second beam transportpotential is a positive potential relative to the reference potential ofthe workpiece W.

That is, the total potential V₁+V₂₋₁ of the first power supply 241 andthe positive power supply 242-1 is applied to the ion source unit 302 asthe second source potential. The positive potential V₂₋₁ is applied tothe beam transport unit 304 as the second beam transport potential.Therefore, the energy E_(EXT) of the ion beam extracted from the ionsource unit 302 to the beam transport unit 304 is E_(EXT)=qV₁, where qis the charge of ion. The final energy E_(IMP) is E_(IMP)=q(V₁+V₂₋₁).

At this time, as indicated by a solid arrow in FIG. 17, a second currentpath 404 is formed such that the beam current flowing from the ion beam307 to the workpiece W is returned to the ion source unit 302. Thesecond current path 404 is a path that starts from the workpiece W,passes through the ground portion 406, the positive power supply 242-1,the second switch 252, the connection point 316 (beam transport unit304), the first switch 251, and the first power supply 241 in thisorder, and reaches the ion source unit 302. The direction of the currentis consistent with the polarity of each of the first power supply 241and the positive power supply 242-1. Thus, the second current path 404can return the beam current from the workpiece W to the ion source unit302.

On the other hand, in the low energy mode, as illustrated in FIG. 18,the first switch 251 is switched to the first state and the secondswitch 252 is switched to the first state. The first switch 251 connectsthe negative terminal of the first power supply 241 to a site having thepotential of the workpiece W so as to form the first current path 402 inthe low energy mode. The second switch 252 connects the second powersupply 242 to the beam transport unit 304 so as to apply the negativepotential to the beam transport unit 304 in the low energy mode.

As a result, the reference potential of the ion source unit 302 is setto the ground portion 406, and the potential of the beam transport unit304 is set to the negative potential relative to the reference potentialof the workpiece W. The first power supply 241 is disconnected from thebeam transport unit 304 and is connected to the ion source unit 302. Thepositive power supply 242-1 is disconnected from the beam transport unit304, and the negative power supply 242-2 is connected to the beamtransport unit 304.

In this manner, the low energy mode is determined such that a firstsource potential is applied to the ion source unit 302, and a first beamtransport potential is applied to the beam transport unit 304. The firstsource potential is a positive potential relative to the referencepotential of the workpiece W. The first beam transport potential is anegative potential relative to the reference potential of the workpieceW.

That is, the potential V₁ of the first power supply 241 is applied tothe ion source unit 302 as the first source potential. The negativepotential V₂₋₂ is applied to the beam transport unit 304 as the firstbeam transport potential. Therefore, the energy E_(EXT) of the ion beamextracted from the ion source unit 302 to the beam transport unit 304 isE_(EXT)=q(V₁−V₂₋₂). The final energy E_(IMP) is E_(IMP)=qV₁.

At this time, as indicated by a solid arrow in FIG. 18, a first currentpath 402 is formed such that the beam current flowing to the workpiece Wis returned to the ion source unit 302. The first current path 402connects the site having the potential of the workpiece W to thereference potential of the ion source unit 302 so that the potential ofthe workpiece W is used as the reference potential of the ion sourceunit 302. The first current path 402 is a path that starts from theworkpiece W, passes through the ground portion 406, the first switch251, and the first power supply 241 in this order, and reaches the ionsource unit 302. That is, the first current path 402 bypasses the secondpower supply 242. Therefore, the first current path 402 is formedwithout using the resistor, and the beam current can be returned fromthe workpiece W to the ion source unit 302.

The path to apply the voltage to the ion source unit 302 in the lowenergy mode is used as the first current path 402. Therefore, it is alsoadvantageous because it is unnecessary to provide additional elementsfor forming the first current path 402.

Also, the return path of the beam current is provided in each of theplurality of energy settings, which can help suppressing the charging ofthe workpiece W in each setting when the ion beam 307 is irradiated onthe workpiece W.

FIG. 19 is a diagram illustrating a schematic configuration of an ionimplantation apparatus 500 according to an embodiment of the presentinvention. The ion implantation apparatus 500 is substantially identicalto the ion implantation apparatus 400 in terms of the return path of thebeam current. In FIG. 19, the operations of the first switch 251 and thesecond switch 252 in the high energy mode are indicated by a solid line,and the operations thereof in the low energy mode are indicated by adotted line.

The ion implantation apparatus 500 has a slightly differentconfiguration from the ion implantation apparatus 400 in terms of thebeam transport unit 304. In the beam transport unit 304 of the ionimplantation apparatus 500, a variety of devices, such as a beamconditioning device 502 and/or a vacuum pump 504, may be mounted. Thesedevices and the beam transport unit 304 may be installed within ahousing 506. Like the beam transport unit 304, the housing 506 isinsulated from the ion source unit 302 by the first insulating support308, and is insulated from the implantation processing chamber 306 bythe second insulating support 310. The beam transport unit 304 ismounted in the housing 506 such that the housing 506 has the samepotential as the beam transport unit 304. The second power supply 242 isconfigured to apply the positive or negative potential, relative to thereference potential of the workpiece W, to the housing 506 and the beamtransport unit 304. Also, a third power supply unit 233 is providedwhich applies a potential to the beam conditioning device 502, with thehousing 506 being set as the reference potential. The housing 506 maybe, for example, the terminal 216 (see FIG. 5). The beam conditioningdevice 502 may be, for example, the beam parallelizing mechanism 211(see FIG. 5).

FIG. 20 is a diagram illustrating a schematic configuration of an ionimplantation apparatus 600 according to an embodiment of the presentinvention. The ion implantation apparatus 600 is substantially identicalto the ion implantation apparatus 400 in terms of the return path of thebeam current. In FIG. 20, the operations of the first switch 251 and thesecond switch 252 in the low energy mode are indicated by a solid line,and the operations thereof in the high energy mode are indicated by adotted line.

The ion implantation apparatus 600 has a slightly differentconfiguration from the ion implantation apparatus 400 in terms of thebeam transport unit. As illustrated, the beam transport unit of the ionimplantation apparatus 600 maybe divided into a plurality of portions.The ion implantation apparatus 600 includes a first beam transport unit602 and a second beam transport unit 604. The first beam transport unit602 is provided in the upstream side of the second beam transport unit604. The first insulating support 308 is provided between the ion sourceunit 302 and the first beam transport unit 602. The second insulatingsupport 310 is provided between the first beam transport unit 602 andthe second beam transport unit 604. The second beam transport unit 604is connected to an entrance of the implantation processing chamber 306and has the same potential as the implantation processing chamber 306.

Abeam conditioning device 606 is disposed in the second beam transportunit 604. A power supply may be provided for applying a negativepotential V_(B) to the beam conditioning device 606. The beamconditioning device 606 may be, for example, an AD column 212 and/or anenergy filter (AEF) 213 (see FIG. 5). The beam conditioning device 606is provided for suppressing a space-charge effect of a low energy ionbeam and efficiently transporting a low energy ion beam.

As described above, in the present embodiment, the ion implantationapparatus is configured to be capable of switching the plurality ofenergy settings. The high-voltage power supply system of the ionimplantation apparatus includes a plurality of current paths formed suchthat the beam current flowing into the workpiece is returned to the ionsource unit. Each of the plurality of energy settings is associated withone of the plurality of current paths, and the corresponding currentpath is selectively used under each energy setting.

The plurality of current paths includes a first current path for thefirst energy setting and a second current path for the second energysetting. Therefore, the return path of the beam current is secured ineach of the low energy mode and the high energy mode. This helpspractical application of the ion implantation apparatus configured toswitch the high-current ion implantation apparatus and themedium-current ion implantation apparatus by the setting change. Inparticular, the formation of the current path without the returningresistor in the low energy mode is practically effective because theinstallation cost and/or the installation space for such a resistorare/is unnecessary.

Also, in an embodiment, the plurality of energy settings may include athird energy setting suitable for transport of a high energy/highcurrent beam, and/or a fourth energy setting suitable for transport of alow energy/low current beam. In this case, for example, the secondcurrent path is used in the third energy setting, and the first currentpath is used in the fourth energy setting. Alternatively, apart from thefirst current path and the second current path, third and/or fourthcurrent paths may be provided for the third energy setting and/or thefourth energy setting.

It should be understood that the invention is not limited to theabove-described embodiment, but may be modified into various forms onthe basis of the spirit of the invention. Additionally, themodifications are included in the scope of the invention.

Priority is claimed to Japanese Patent Application No. 2013-177625,filed on Aug. 29, 2013, the entire content of which is incorporatedherein by reference.

What is claimed is:
 1. An ion implantation apparatus comprising: animplantation processing chamber for implanting ions into a workpiece; ahigh voltage unit comprising an ion source unit for generating the ions,and a beam transport unit provided between the ion source unit and theimplantation processing chamber; and a high-voltage power supply systemconfigured to apply a potential to the high voltage unit under any oneof a plurality of energy settings, wherein the high-voltage power supplysystem comprises a plurality of current paths formed such that a beamcurrent flowing into the workpiece is returned to the ion source unit,and each of the plurality of energy settings is associated with acorresponding one of the plurality of current paths.
 2. The ionimplantation apparatus according to claim 1, wherein the plurality ofenergy settings comprises a first energy setting suitable for transportof a low energy ion beam, and a second energy setting suitable fortransport of a high energy ion beam, and the plurality of current pathscomprises a first current path formed such that a beam current flowingfrom the low energy ion beam to the workpiece is returned to the ionsource unit.
 3. The ion implantation apparatus according to claim 2,wherein the plurality of current paths comprises a second current pathformed such that a beam current flowing from the high energy ion beam tothe workpiece is returned to the ion source unit.
 4. The ionimplantation apparatus according to claim 2, wherein the first currentpath connects a site having a potential of the workpiece to a referencepotential of the ion source unit, such that the potential of theworkpiece is used as the reference potential of the ion source unit. 5.The ion implantation apparatus according to claim 2, wherein the firstcurrent path comprises a first power supply which applies a positivepotential to the ion source unit, a positive terminal of the first powersupply being connected to the ion source unit, and the first currentpath comprises a first switch for connecting a negative terminal of thefirst power supply to a site having a potential of the workpiece so asto form the first current path under the first energy setting.
 6. Theion implantation apparatus according to claim 5, wherein the firstswitch connects the negative terminal of the first power supply to thebeam transport unit under the second energy setting, and a secondcurrent path of the high-voltage power supply system is formed so as topass through the beam transport unit and the first switch.
 7. The ionimplantation apparatus according to claim 6, wherein the second currentpath comprises a second power supply which applies a positive potentialor a negative potential, relative to a reference potential of theworkpiece, to the beam transport unit, and a second switch whichoperates in synchronization with the first switch, and the second switchconnects the second power supply to the beam transport unit so as toapply the positive potential to the beam transport unit under the secondenergy setting.
 8. The ion implantation apparatus according to claim 7,wherein the second switch connects the second power supply to the beamtransport unit so as to apply the negative potential to the beamtransport unit under the first energy setting.
 9. The ion implantationapparatus according to claim 2, wherein the low energy ion beam is a lowenergy/high current beam, and the high energy ion beam is a highenergy/low current beam.
 10. The ion implantation apparatus according toclaim 2, wherein the first energy setting is determined such that afirst source potential is applied to the ion source unit and a firstbeam transport potential is applied to the beam transport unit, thefirst source potential is a positive potential relative to a referencepotential of the workpiece, and the first beam transport potential is anegative potential relative to the reference potential of the workpiece.11. The ion implantation apparatus according to claim 2, wherein thesecond energy setting is determined such that a second source potentialis applied to the ion source unit and a second beam transport potentialis applied to the beam transport unit, the second source potential is apositive potential relative to a potential of the beam transport unit,and the second beam transport potential is a positive potential relativeto a reference potential of the workpiece.
 12. The ion implantationapparatus according to claim 2, wherein the first current pathcomprises: a second power supply which applies a positive potential or anegative potential, relative to a reference potential of the workpiece,to the beam transport unit; and a resistor which is provided such that abeam current flowing from the low energy ion beam to the workpiece isreturned to the ion source unit through the second power supply.
 13. Anion implantation method comprising: selecting one of a plurality ofenergy settings; applying a potential to a high voltage unit of an ionimplantation apparatus, based on a selected energy setting; andimplanting ions into a workpiece under the selected energy setting,wherein the ion implantation apparatus comprises a plurality of currentpaths formed such that a beam current flowing into the workpiece isreturned to an ion source unit, and each of the plurality of energysettings is associated with a corresponding one of the plurality ofcurrent paths.